The Green Giant’s Growth Habit
Perhaps I’ve said it before, but it’s extremely helpful when you know what a plant’s growth habit is before you prune. Growth habit is basically the shape a plant naturally wants to grow into and how the branching structure supports that shape. For example: Arborvitae ‘Green Giant’ is pyramidal in form and proportionately much taller than wide. As a matter of fact, this plant will easily get to 30′ tall and 15′ wide in thirty years. Rapid grower…I think so. Its branching structure is horizontal with some ascending branches as well.
Other characteristics about the plant can be helpful too when deciding your pruning strategy. For instance, Arborvitae ‘Green Giant’ prefers more light (full sun is ideal). The less light it gets the thinner and more open its branching and foliage will be. Prune less aggressively if you know the plant is adapting to less than ideal conditions.
The Pruning Strategy
Let’s assume the ‘Green Giant’ you’re going to prune has been positioned to have enough room to grow and stay somewhat within its “natural boundaries”. If the space is too limited and there’s no future for the plant in that spot, think about transplanting it.
To give ‘Green Giant’ a strong trunk and branching structure, it’s important to prune them in their early years. In the first picture above, these Arbs were undoubtedly pruned early on in their lives. Notice how full they are from the ground to about 4/5ths of their height. However, the last growth at the top is thin and “stretched-out”. This is very typical of rapid-growth plants.
It is this top growth (upper 1/5th) that needs pruning. You should also scout the lower portion of the plant for any branch ends that may have grown more aggressively than others. There should not be many.
I apologize for the picture quality of these “before” and “after” shots, but even the silhouette conveys the degree of pruning I did.
I used a traditional trimming shear along with an orchard ladder. By today’s standards you might call that “old school”. I still think a good quality hand shear gives the best cut and, of course, with total control. I did, however, think how convenient and productive a telescopic gas powered shear would have been. Just take care as those power shears can cut aggressively.
The main goal and concept here is to trim the ends of the longer, fast growing branches to shape the plant and encourage fuller growth.
This is what plant nurseries do while they’re growing the plants for market. You want to continue this trimming routine for as long as it is practical. The idea is to develop a full, nicely shaped plant so that it can continue to grow on its own with this strong foundation you’ve help create.
I have a maintenance business and I get asked to trim on most of my accounts. I don’t mind doing it but I really don’t know exactly how they all should be trimmed. This article on arborvites is excellent and clears up that plant. I think this type is on some of the properties I cut. I found other things you wrote about trimming and they are good to. Keep it up.
Justin, I’m so glad you got something out of this article on ‘Green Giant’ Arbs. and some of the others I did on pruning. I’ll continue to post articles on pruning. This is such a broad aspect of gardening and landscape care. Rarely is pruning done correctly. You should explain to your customers (when you can) that you’re pruning based on each plant’s needs & requirements. They will be so grateful (and impressed!) that you’re doing it correctly.
I have a Pyrmidial Arborvitae (sp), that is getting too tall for the present location. How can/should I lessen the height? They are about 10 feet tall, and I’d like to take them to about 6 feet. Is this possible?
Sometimes I’ll plant a particular plant-type knowing straight-off it characteristically wants to get taller than my “design intent”. This is rare, but I’ll do it because I know that a diligent program of proper pruning can make this plant conform (to some acceptable degree). A key factor in being able to “get away with this” is starting with a young plant and introducing it to this “discipline” early on.
Having said all this, I don’t recommend you cut this Arb. down so severely. If possible I’d transplant it (or them) to a location where they can grow tall, and in its place install a better suited plant for the size you ultimately want it to get. For example, there are fastigiate varieties of boxwood that will grow rather narrow and easily be maintained 6′ or so.
Great article, thanks! I have 8 green giants planted along a fence line on my property. They are about 12-15 feet tall now and I have already cut a foot off the top last year. They are growing into eachother and into the fence behind them. I want to keep it as it is now – a solid privacy wall about 15 ft. high.
A couple questions – do I need to trim them back at all between each other and the fence in order to keep them from growing too far into one another and dying?
Also, what is the best power tool to use to trim green giants? Power hedge trimmer or power pruner? Whichever one would obviously need a long telescoping pole to extend a good distance to reach the tops. Would a 20volt battery powered trimmer / pruner be powerful enough?
Thanks for any tips you have!
Your Arborvitae ‘Green Giants’ are obviously doing well and they therefore want to continue growing to their potential, i.e. taller and wider.
I’m more concerned about their distance from the fence than from one another. On property lines where there is no fence, typically the neighbor does not mind you (or a maintenance co.) coming over to prune & maintain the plants. With the fence there it makes it difficult to prune and care for the backside of the plant. The fence limits the growth, and often the plant declines in this lower area. It will most likely continue to grow upward and in the front, but not ideally all-around.
I’d have to see the situation and understand the distance and other circumstances related to the property line and fence to give specific advice.
It sounds like diligent and aggressive pruning is important here. I would be set-up with a telescopic trimmmer, strong step ladder and maybe a pole pruner too. The pole pruner would assist where certain cuts become too thick for the trimmer. And just like with any selective pruning you can strategically make cuts back into the plant to reduce the thick branches that are close to the outer ends of the plant. The pole pruner works well for this.
I just bought a new telescopic pruner (ARS LA-180ZR203 4-to-7-Feet Long Reach Pruner) for myself. Here’s the link on Amazon. I really have not tested it yet, but the reviews seem good. This type of pruner would probably work well for you too – serving more in line with what the pole pruner would do, but more efficiently.
Hope this helps.
I have an 8′ tall hedge of Green Giants. Several plants were damaged when a tree fell on top of them, bending and cracking the upper two thirds of the trunks. I cut away the upper two thirds. What remains is about 2.5 feet high and 4 feet wide. The root system is intact. Will new growth appear only from the existing green tips or is new growth possible from the main trunk itself? Thanks.
You may have some new growth sprouting closer to the main stem, but if you are intent on saving the plant(s) this is what I’d do. The tree wants to create a new leader or central stem. And for the long-term development it should have one. I would check to see if one of the remaining upper branches could be gently bent and trained to gradually assume that central leader role. A guide stake could be installed next to the trunk as a vertical support. Support the branch you select carefully against this stake with a gentle, but persuasive bend towards vertical. Now it could be that you have to do this process incrementally over 2 seasons or so to attain and persuade that one branch to go completely vertical.
I have over 40 3-4′ Green Giants planted for a privacy fence. I have noticed probably half of the trees planted have multiple vertical leader of the same height. What is the best way to prune the tree to promote one central leader? Any help would be great. Thanks!
If you plan to let them get large it probably makes sense to try and deal with those “co-dominant” leaders. Here’s a good article on what the concerns can be for co-dominant stems and some pointers on pruning them.
At 3-4′ you don’t want to wait any longer.
So ideally it would be best to eliminate the competing stems entirely. With these plants’ young age they should recover with future growth. There is another technique called “subordination” where you stunt the competing stems (not removing them entirely), which lets the one you want become the dominant leader. This technique may be one you use when eliminating the entire stem(s) may disfigure the tree too much.
I have nine Green Giants planted about 4-5 feet apart to create a privacy screen. Right now they are about seven feet tall. I chose this variety to create a barrier to the street for my kids and some privacy from the neighbors. I also hoped to maintain some of the exposed sunlight for the yard so that we don’t lose our grass and can grow a garden. I have read conflicting reports on how tall my trees are likely to grow. Is there a way that I can gently prune them so that they are not as apt to grow beyond 15-20 feet or so? Or am I too late to train them? Even at 20 feet, because of the cone shape, I’d likely still get about five feet of sun peaking through though right? Thank you.
You should be fine maintaining them so that they don’t grow beyond 15-20 feet, but it will require your attention and consistent pruning.
It’s great that you’re aware of the Green Giant’s potential and taking steps early on. By selectively pruning the top, central leader and then proportionately the lower portion of the plant you’ll keep its growth in-check. You did say “gently” prune, but I would not hesitate to make strong, proper cuts where required. The fact that you’re aware and starting this pruning campaign early on is a real advantage. Well done!
Hi Roger…..great article. Thanks for the tips. I planted 12 Green Giants a month ago and have about 6 inches of new growth already. Like you mentioned the top fifth of the tree is outpacing the rest. The Arb in your before pruning pic is fuller than what I have. Some of the main leads have a litte growth but are about 2 feet above the next set of full branches. They are about 6- 7 1/2 ft tall. I want to create a shorter fuller tree while they are manageable. How much can I remove off the center lead without damaging the tree? Is it safe to trim or wait until it has become established? Thanks in advance!!
Yeah, I’ve seen many Green Giants “stretch-out” like that. It’s good you’re aware of that tendency with this plant at this young stage. And they are relatively young at only 6-7 1/2′ tall.
I would accept the 2 foot stretch/gap above the next set of full branches, but prune back whatever growth is at the top to temporarily stunt the plant. You’ll most likely need to also prune the lower growth to keep things in proportion and scale.
You may have to keep up this strategy of stunting the top growth for a season or two to let the rest of the plant catch up and fill out (and it will).
I have a dozen 6′ Green Giants that were submerged under 3-4′ of salt water during Sandy. The inner part of each branch appears bright green and healthy, but the outer two inches are brown. Can I trim off the brown or should I allow it to fall away naturally over time? Thank you.
The fact that there’s healthy green growth on the interior is a good sign. I would selectively prune the outer portions that are lifeless.
This plant has a moderate tolerance for salt and by now the salt has been leached out of the ground through time and rainfalls. I’ll bet they’ll be fine.
I would not fertilize the plants as you would be introducing “salt” in another form right back into the soil. Give them 1 to 2 seasons to recover naturally on their own.
I have about 25 8 to 9 foot Green Giants that I bought last year. The upper half of these trees are very thin and I was told at a nursury to cut about a foot off the leader stem to get them to thicken out. I want to make sure these still grow taller from the leader. Ultimately I would like tham about 12 – 14 feet tall. Is this the right approach to cut of new growth off the central leader where the leader and another brach intersect? That is what I was told but I dont want to ruin the tree from continuing to grow taller. Thanks so much for your help!
I have 25 8 to 9 foot green giants that I planted last year.. The top half of the trees are very thin. I was told at a nursery to cut the top foot off the central leader where the leader meets another branch to thicken the trees. I want to make sure the trees still gro taller (ultimately to 12- 14 ft). Is cutting the leader a good idea? if so is it too late in the season to do this?
You should be fine doing what the nursery is recommending. Cutting 1′ from the central leader (to just above a branch juncture) should not affect the “dominance” of the central leader. And now is a good time.
if your planting arbs in a row for a property line…how far apart should they be planted?
is there a way to prune/trim an established arb, say 5-6 feet tall, to grow thicker and fatter?
Spacing for planting depends on the variety of Arborvitae.
If you’re using ‘Green Giants” I would not plant any closer than 8’ center-to-center. There are other varieties similar to ‘Green Giant,’ such as ‘Steeplechase’ that you could go a little closer with…perhaps 6′ center-to-center.
If you need tighter spacing for immediate screening, choose a variety that naturally stays narrow (like ‘Emerald Green’) and space them 4′ center-to-center.
Pruning/trimming is not really the deciding factor on how wide an Arb. will get. Width is predetermined by the variety you choose. Certainly some proper pruning can influence the fullness of the plant to some degree.
Great tips, but unless I’ve missed it, I do not see a ‘when to prune’ tip. Dormant season recommended?
We do most of our pruning in late summer after the new growth has hardened-off. You certainly have other opportunities throughout the year, including winter. This plant would not be as particular in terms of pruning time as a flowering plant might be. And although one could take the discussion/argument even further, my experience shows me the plant is not that particular.
I have five Spring Grove Western Arborvitaes, each about 7-8 feet tall. They were planted a year ago and have grown probably two feet in that time. I have noticed that two of the plants have a “double leader”. I would like to remove the secondary leader to encourage growth of one dominant central leader. Is this time of year (late July) an acceptable time to do this?
Thanks for the great information!
I forgot to ask in my last post-
Can I remove 1′ off the top at this time of year? I am trying to get fuller top growth as described above.
Rather than suggest to remove a particular amount like 1′, I’d advise that any amount would have a beneficial affect on the plant. Just removing the very ends/tips of the latest growth will remove the apical buds and cause the plant to put more energy into the lower, lateral growth.
Whatever amount (e.g. one foot, 6 inches, etc.) seems appropriate and, most importantly, in proportion to the plant in terms of its size and shape, that’s where you can make your cut(s).
So if it won’t harm the plant to trim the top growth by trimming at this time, can I assume it would be okay to prune the secondary leader at this point?
Yes, Mike. However it will be next year’s growth that begins to fill in and give you the results you’re looking for.
I have a new neighbor that moved in and cut down about 20 15′ beautiful Arborvitae that provided so much privacy!! We do have a 6′ stockade fence but that’s not providing much as our yard is a bit higher up then his so we are looking right into his yard now! We are deciding between Emerald Green’s and perhaps Green Giants. I like the Emeralds because they don’t take up too much yard but will have to buy many more then the Green Giants to get the instant privacy and that will be pretty expensive!
If I were to buy 8′ Green Giants, can I keep them sheared to maintain about a 12′ height and about 6′ width?
And on the Emeralds, I saw some beauties at our nursery yesterday, they are about 8′-10′ high but they never trimmed them to have only one leader, is it to late at this stage to trim back the others?
Sorry to hear about the Arbs. getting cut down. People can do the craziest things.
Emerald Green does stay narrow, but it characteristically has multiple stems – as do some other Arborvitae.
You would be challenged to keep Green Giants 12′ high and 6′ wide.
There is a cultivar of Green Giant and it’s called ‘Steeplechase’. It typically has a central leader and yet it grows relatively narrow (5 – 8′). Try to locate this plant and I think you’ll have the perfect Arborvitae for your hedge.
Thank you so much!! I will definitely look for the Steeplechase!!!!
Great article! We are planning to plant an 18′ green giant to get 2nd floor privacy. The tree is about 5.5′ to 6′ at the bottom. We really want to keep the tree at 25′ height and 6′ wide ultimatelt and planning to plant it as close as 4 feet to the house. How frequently do we need to prune the tree to keep it at this height and width? Would it be very challenging?
If you are using ‘Green Giant’ in this application you will have to be diligent with your pruning.
I’m not so concerned about controlling the height as I am about the width. If the plant is currently 18′ and you plan to plant it so the current foliage is 4′ from the house, you should be OK. If you intend to plant so the “center” of the plant is 4′ from the building, that’s too close.
At a minimum I would plan on one good pruning per year. And again, you’ll need to prune “selectively” by hand so you can choose dominant stems & branches and cut them back to a lower branch or leaf node. Shearing the plant will not give you good results.
There are other similar varieties and cultivars of Arborvitae that will stay more narrow. Arborvitae ‘Wintergreen’ is just one of them.
This is such helpful information! We just planted seven 10′ green giants and are also looking for second floor privacy (which we won’t start getting until the trees are around 20 feet tall).
Are there any pruning tips to ensure fast, steady growth?
Thank you so much!
‘Green Giants’ are very hardy and dependable. If they’re getting plenty of light, and occasional moisture during dry weather, they should grow rapidly. Of course they’ll need to “take root” and establish to grow at this optimum rate. That usually takes a year or two.
In terms of pruning: again, I would just “tip” the newer, upper growth to encourage the plant to push growth from lateral buds. In other words, grow full and strong.
I have about 10 green giants that about 3-5 years old and 8-9 feet in height and quite thin. I want to trim the leader so they can put on some weight.How far/close above the lower branch should the leader be pruned to(approximately in inches)? Is there a guideline? If there is a guideline, what is the reason for the guidline?
Also, the trees have not been previously pruned. There are a couple of trees where the main trunk is curved into a flattened C (although they were staked, they have grown higher than the stakes). Is this a problem or will it straighten out as it grows.
Appreciate your advice!
I’d hesitate to give any measurements for pruning the leader – it varies and is really a judgement call. Take another look at the before and after pictures in the post and notice in the “after” pic the relationship between the tip of the leader and the first lower lateral branch.
You can remove the stakes and let the plants develop naturally, but with your pruning. The trees will straighten and strengthen as they grow. Any existing bends should not affect the plant in the long-term.
Great article! I have a row of 22 green giant arborvitae that I had planted as a privacy screen. I had 7 of them planted first in the corner of my yard about 3 years ago, and the others planted a year later. The first seven that were planted look different than the others (not as good). They look thinner (not as dense), and the foliage is droopy. In the winter they turn a more golden brown color. I’m thinking that they might be a slightly different variety than the others. I want them to become thicker (denser) and less droopy. Would sheering them help? I was thinking of doing this in the spring.
Do you remember if the first 7 Arbs. looked different (better) when they were first planted 3 years ago? Sometimes the environment (soil type, exposure, etc.) is different from the nursery they were grown, and they then change a bit while adapting to the different conditions. But you may be correct that the other Arbs are a different variety. As you may know there are many varieties of Arborvitae, and I believe there occurs variations even within those varieties.
You could try to shear them lightly in the spring – that could encourage lateral buds and growth to thicken them up a bit. The droopy foliage is probably something the plant will continue to have.
I have a privacy screen of 13 Green Giants planted in full sun against a 6′ wood fence about 11 years ago. They make a beautiful dense screen and are about 25′ tall X 9′ wide–the McMansion uphill behind our home is completely blocked! My garden isn’t the biggest and I’d like to limb them up about 5′ to allow enough light underneath to plant the area (and it would make the garden feel bigger). Can I do this without compromising the strength of the tree? I’m in the Washington DC area so we get run share of snow (usually).
I’ve never “limbed-up” a Green Giant Arb so I can’t comment on the appearance. At 25′ the Arbs are certainly tall enough that raising their canopy 5′ should look acceptable (and not disproportionate) And doing so should not damage the tree health-wise.
Here is a picture of an American Holly I limbed-up. I think it’s important the tree (to be limbed-up) be substantial in size, and the upper growth should be loose and informal. If you shear and shape them it could look rather peculiar limbed-up. If you let them continue to grow and develop naturally I think they’ll look OK.
Take the time to envision what it might look like. Maybe have someone hold down some the the branches you intend to remove just to get some sense of a raised canopy look. In the end you’ll have to use your aesthetic judgement.
We are about to have a Nursery plant 7 Green Giant Arb for a screen between a neighbor. They have 6-7 foot and 12-14 foot as options. The price is roughly $1,500 higher for the taller ones. It would be nice to have the 12-14 foot arb but is it better to put in smaller ones for some reason besides price. Thanks!!
First off I would tell you that in our market here in the New York area, a $1500 overall difference to plant 7 of: 12-14′ Green Giants vs. 6-7′ is a fantastic deal. Frankly, I’m not sure how they’re able to offer that. Of course I don’t know the market you’re in or the circumstances such as where the plants are coming from, what quality they are, etc.
The cost of larger plants alone (7) for the installer would be $1500 +/- in our NY area. Then, as an installer, you have to deal with the increase in installation time and greater equipment needed to handle them.
If you’ve seen the plants and they’re acceptable, and you get a guarantee, then I would go with the 12-14′ arbs. If the plants are from a reputable grower/nursery so that they’re grown and dug properly, you should have 100% success with them. Early spring is an excellent time to plant.
I’m planting a row of 12 8′ Green Giants along my fence line to screen out a new home next door. The grower is recommending they be planted 8-10 feet apart. How long would it take 8′ AVGGs to grow together to form a decent screen when planted 8 feet apart? And would you recommend that I plant them 8 feet apart – centered with each fence post – or 10 feet?
There’s a potential that the home builder will plant some staggered with my own on the other side of the fence, but who knows if that will actually happen.
Thanks for your advice!
8′ is a good spacing for ‘Green Giants,’ and the one I use frequently. I like 8′ because it’s a nice compromise with spacing properly for the plant’s health & development, and looking “reasonable” at installation. 10′ would be good too (considering the growth potential of ‘GG”), but that spacing is going to look a little too great at installation, especially for 8′ high plants.
Also, consider the distance from the fence to the center of each plant. I would say no closer than 5’. And if your yard was large and expansive, I would even consider bringing them out a little further from the fence.
Arb “Green Giant” is typically a fast grower. I’d estimate that the 8′ high “GG” Arbs will touch in 3 years. And I’d expect decent screening in 5 years.
We had about 6 of these plants planted last fall by a local nursery. So far, so good. They told us to prune the top leader in the spring, which I have already done for 2014 (for bottom fullness.) I did about a foot, maybe a little more. What I didn’t do, is to cut them at the ‘V.’ Will that be a problem for my trees or will they bounce back and the leader will continue to grow? I am hoping that it will be ok!!
Jessica, that should be fine. Often we can’t reach the tops to be so precise with our cuts either. The plants will continue to push new growth and maintain a leader.
I have about 35 green giants lining my backyard that provide tremendous privacy. They are sturdy trees and look very healthy, the problem is that the tree have grown to 30-35 feet. I bought the house with the trees installed close to 2 years ago. A friend recommended I take a few feet off the top of each tree. What would you do to control the growth or even reduce the current heights?
You could prune the top leader back to a certain point. It’s hard to give a definitive amount to cut back because situations vary. But think in terms of always maintaining a pyramidal form. So prune the top (crown) as a whole and see how the aggressive shaping at the top (maintain the leader and pyramidal form) allow you to cut back the leader’s height. I hope that makes sense. I really have to start doing simple videos to demonstrate things like this.
I have an old tall arbitrary hedge. I have never sheared it. Today I saw that some critter got into the tops of several and chewed off many branches, about ten feet up. Will those bare spots grow back? It looks terrible now!
Tough to tell without seeing it. You’ll have to wait and see – so hold-off on any corrective pruning till the season progresses and you clearly see what’s living and what’s not.
The plant can push new buds and growth in some circumstances. However, any stems or branches that had their bark stripped off will likely die back. This outer layer (cambium) transports nutrients, and when it’s removed that causes that section of the plant to die.
It’s those portions of the plant with bark remaining where it’s possible to re-bud.
We have 30 foot arborvitae that the deer have eaten from the base to as high as they can reach. They have totally stripped the branches and most of them are now dead. Can these dead branches be cut off to leave a trunk of about 4 feet without hurting the plant? Thank you.
Interesting. In our area ‘Green Giant’ is called deer resistant. This is just another example that “deer resistant” plant lists should be taken with a grain of salt. And just the other day I had a long conversation with a person who operates a deer control business. And he was telling me of many instances where deer were behaving differently than industry reports & lists were stating. In short, it’s not an exact science by any means.
To answer your question, yes, you can elevate the trees to remove the damaged lower branches. The tree will be fine. And actually, it can look quite nice.
I planted a row of 12 7′ Emerald Greens last summer and was told to fertilize them in the spring. One person said to use Holy Tone and another said to use Plant Tone, which if either do you suggest? We are looking to get a lot of growth! Thanks!
Arborvitae prefer a neutral pH soil. Plant-tone would be great.
I have what was 2 great trees that took a beating this winter
Can the trees be that are over 20′ be trimmed down to about 8′ and live ?
The trees must be in really bad shape to have to cut them back to 8′.
Without seeing the trees it’s hard to even comment, but this is my thought: If you’re cutting them back from 20 to 8′, I have to believe the tree is not only compromised health wise, but disfigured too. Perhaps you should think about replacing them. At least the new plants (at 8′) will be attractive, healthy and ready to grow.
I ordered Emerald Greens from a mail order nursery years ago and was very happy with the plants, although they were subject to scale on occasion. I’ve been looking around at local nurseries for additional plants, but the Emerald Greens don’t quite match what I received by mail. The local plants all have branches that are oriented to the vertical, whereas my Emerald Greens have branches that are more horizontal, giving a sculpted look that I prefer. Are there different varieties of Emerald Green? Thanks!
I feel your pain. I too have experienced variations in plants when they are labeled the same. I can’t say for sure why this happens, but it’s not uncommon.
Trust your judgement and wait till you find the leaf type and habit of growth that resembles the euonymus you have (and like). It’s great that you’re that observant.
The other day I thought I could diy prune on my green giants. Well my husband said I have ruined the tree. The 2 trees are in my front yard. Right when you walk in. I didn’t trimmed them since I lived here for the past 2 years I lived here and IM pretty sure no one did before I moved in. The growth was so crazy I couldn’t walk into my house without bumping into them. So I borrowed a friends hedge trimmer and got to town. Parts I had to cut off to walk into my house are not “green” its the stick part. My husband says I ruined the tree. But I have researched that the tree is a rapid grower. Will the tree regrow the green? Did I damage the tree? I cut so much of it off.
Hard to say without seeing it if the plant will recover in the areas cut back severely.
It sounds to me as though they’re simply in the wrong spots. Any chance they could be transplanted?
Just planted mine this past April of 2014. They are 8 feet in height. What time of year should I prune them? I live on Long Island NY.
We do most of our pruning in late summer.
We live in New Rochelle New York. zone 6. We need a fast growing deer resistant hedge and the landscaper is recommending Arborvitae Green Giant. The problem is I never want it to get higher than 10 feet or so. Can we keep it pruned to that level?
Arb. ‘Green Giant’ would be impossible to keep within 10′. You might consider Skip Laurel (Prunus laurocerasus ‘Schipkaensis’).
Hi Roger — I am afraid we messed up!
We planted some 8 foot green giants last fall and they did amazingly well — grew about 1 foot in 6 months, but super skinny growth on top and quite thinned out. We tried to follow the pruning instructions and cut the skinny part down about 10 inches to help encourage full growth, but now about 3 weeks later, some of the branches that previously were below the top point after the cutting (so previously helped shape a pyramid) have now grown higher then the top point.
I am concerned this might create a double leader and that the original “top” leader won’t grow. Can we trim the other branches back a bit (both vertically and horizontally) to get the pyramid shape at the top back? Is there something else we should do? Thank you again for all of your advice and help!
Perhaps that first cut of 10″ was a bit much for an 8′ high plant, but I still think you’ll be OK.
I would do some additional pruning/shaping, as you’re thinking, on the growth at the top and moving downward. Envision the pyramidal form to the top and draw an imaginary line to that effect. Prune/trim to follow that imaginary line. Don’t feel you have to get it cut way back to make the remaining central leader at the very top – that could be too aggressive on the nearby growth. Think of it as a “beginning campaign” to eventually allow the central leader to dominate…as it should. This could take another year or two for it to happen.
Hello. We just set out 9 Thuja Green Giants along a 45-foot fence row. They are planted about 6 feet from the fence. We want the trees to reach a final growth of about 18′ x 8′. Can this be achieved with pruning, and if so, when do we start pruning them and how? They are very tiny now.
I think your plan to have the GG’s grow to 18′ X 8′ is realistic, however, not without controlling them with pruning.
Start now by just tipping the end growth with shears to encourage fullness. I would take note of the size each season just so you have a record of how fast (and big) they’re growing. This will be helpful in understanding their rate of growth and guiding you as to how much (and how aggressively) you should be pruning them.
They’ll come a point where you’ll need to prune decisively to keep them in check.
Hello out there.
Should I prune my Green Giant so that it has one main trunk?
Currently it has one large trunk and two smaller ones with all three starting at ground level.
Depending on how old and tall the plant is, removing the 2 smaller leads may be too drastic a step.
Alternatively you could allow the 3 stems to remain. With multi-stem arborvitae we use a product called Arbor Tie to make a supportive loop about 1/4 from the top of the plant. You can discreetly weave the Arbor Tie inside the plant branching around the 3 stems. This will prevent the 3 stems from splaying apart, particularly when it snows heavy. Every 3-5 years you should check on the Arbor Tie because it may have to be moved or adjusted as the plant grows. Do not use rope, twine or wire for this – it will harm the tree.
Last fall I wanted to trim my pyramidal’s so they would be straight across. My friends (they still are) topped the center instead and they look awful. Will the outside grow up (eventually) to cover the ugly stick now showing? I’m so sad that they wrecked the nice shape.
I’d have to see them to give a better comment, but it sounds like your friends cut the center stalks fairly low.
The tree(s) should instinctively grow and branch-out where that cut was made. If you want them to get taller you should notice one or two branches aspiring to become dominant and grow upward. You could allow this to happen and slowly get back to a single, dominant leader.
If the height is close to where you want it, you’ll end up continuing to trim the newer growth that occurs in that area to control the height. Eventually this should all fill in at the top and hide the cut.
Hello Roger, great information. I have seven Giant Arborvitae that were planted five years ago. I fertilize they and mulched for the first couple of years. They have been growing steadily so I just left them alone. The trees are over fourty feet high and about twenty feet wide. They look good but My question is pruning it. Do I just let them grow. They are not restricted. I enjoy the wildlife that uses it for shelter and they provide privacy.
Those ‘Green Giants’ are living up to their name!
If you have the room to let them grow, they’ll be perfectly fine on their own. The plant typically has one central trunk & leader and grows with a reasonably strong framework.
I’m thinking of using some green giants for a second level deck screen. Is it possible to keep them between 16-20 ft?
I’d hesitate to say that you could keep them at 16-20 ft. long-term. Even with annual pruning they will eventually want to get larger.
Roger, I have a row of 10′ GG planted 8 ft apart. 3 of them have been damaged (broken branches) on one side by a miniature horse rubbing up against them. I have since fenced them off. I’d like to dig up and rotate the trees 180 degrees so that the bare spots where branches were broken are facing away from my house. What do you think about this idea? Would I risk losing the trees from stress? I am replanting them in the same spot, just turned. Thanks!
Yes, you can dig and rotate them. But make sure you’re digging the plant correctly. Also, if possible I’d wait until early fall (Sept.). It will be less stressful on the plants, and yet still give them time to root before winter.
I would like to know if you have any success growing green giants in a heated green house after rooting cuttings in the winter months, by the way you can prune green giants any time of the year how ever you like , they also are actively growing in the winter. They are also sweat soil lovers, water them every day during the growing season and feed them twice a year. Hope to hear back.
I’m not involved in greenhouse growing. Years ago I bought specimen plants (e.g. dwarf conifers, cypress, small-leafed rhodos.) from a local grower who propagated from cuttings in his greenhouses and then moved the rooted cuttings out to the fields. I loved going there to buy, and the quality of the plants was excellent.
Our new neighbors just built a 2-story garage mahal in their back yard and it’s quite an eye sore! We are looking to plant some evergreen trees to block the view and I have been reading about the Green Giant trees. However, I think that these trees will grow too wide for us. I am looking for something tall, but with a with of 5-6 feet. Can we achieve this width with the Green Giant (with some pruning) or do you suggest another type of evergreen that would suit our needs?
Another variety to consider is Arborvitae occidentalis ‘Wintergreen’. It usually has a single, central leader, which is good, and is often referred to as a narrow/columnar growing plant . It will get tall (approx. 30′) and maybe 8′ or so wide at maturity. And actually, I don’t think I’ve ever seen Wintergreen get that wide.
Another plant to consider is Arborvitae ‘Emerald Green’.
If I plant on 4-5 ft centers and the soil is very rocky, is it likely that they will only attain about 20 -30 feet at maturity with a spread of 5-10 feet at the base?
It would be difficult to predict the growth potential of a plant by the soil type. I would say rocky soil on its own is not enough of a factor to significantly change the plant’s size.
Planting ‘Green Giants’ on 4-5′ centers is too close IMO. You’d be better off increasing to 6′ C-C. And frankly, I’d recommend 8’C-C if at all possible. With diligent pruning you could keep the width to 8-10′.
Have you considered a narrower growing arborvitae like ‘Wintergreen’? It would be better suited to your situation.
I would like to build a landscaped privacy wall that blocks the view of the house on a front mounded culvert by the road of my house, I have all the boulders and rockscape in, planted 6 large burning bushes, 20 gems, hundreds of hostas, 2 maples and 2 Kusa dogwoods. Now i need to bring in the tall stuff for the screen… I tried 3 times now to use 12 emerald greens and 3 years in a row, and they have died. NOt sure why!!! The soil on top of the mound is hard, I dug it out larger then the burlap/caged root ball, and back filled with fresh super soil. I am in a wooded area and the front gets morning sun as it comes over my house, then its filtered through the trees, from 2pm on. The Hostas are the only thing up there that is doing really well they are going nuts
I was thinking of switching to the green giants or the dark green arbs. Do you have a recommendation for my situation. I scoured online and cant really make a decision. I like how the green giants look when shaped. I have no problems staying on top of pruining them to keep them looking good
It’s curious why the hosta are the only things doing well. Even in partial shade (or filtered light) the burning bush should adapt and do OK. What do you mean by Gems? And what kind of maples did you plant?
It doesn’t surprise me that the Emerald Greens failed. They, generally, do need more light.
And you can’t rule out other factors. You mentioned the soil — and that could be part of the problem. (BTW, hosta are not too particular.) If you imported the soil, or got it from an excavation on the property, you might want to get it tested.
Water may be a problem too. Especially in the first couple of seasons when plants are establishing themselves.
Arborvitae ‘Green Giant’ is definitely more tolerant of less light. It will, however, grow slower and a bit “thinner” in stature. And that doesn’t have to be a bad thing.
The burning bushes are doing ok they have have grown maybe 12″ in diameter.(this is the third season) But they have never turned red.
They are green gem boxwoods… But I think they are the little larger so possible the winter gem? I bought hundreds so Im not sure which one is up there. I think the bigger of the two. but basically the same thing
I believe the maple is a blood good jap maple. It isnt really doing much at all since I planted it in 2012. This is the same for the KUSA doogwood.
the soil came from the nursery it is their super soil has peat compost etc etc in it Its basically the top soil they have. they hosta are soley planted in this soil..
Since the arbs are on the top of the mound its in the older light brown, orange colored hard stuff…Not clay
I like the green giants, do you think the dark green arbs would be a better fit? I get 4 foot green giants for 20$ and the root ball 6′ dark green arbs are 25$ so its pretty much a toss up as far as money goes.
The ‘Green Giant’ is the better arb of the two.
The boxwood are probably languishing because of the limited light. Also, I would test your soil. It seems to vary depending on where you are in this garden/planting area. If the pH is off, a nutrient imbalance, etc., etc. — these factors can have a profound affect on the plants.
The Kousa and Japanese Maple should do OK in that setting. Again, soil issue? Irrigation issue. Etc., Etc.
thanks for the input roger, I went ahead with the green giants. I will post an update.
I have 5 green giants planted such that the main trunk is only about 3 feet from an established fence and theres only about 2-3 feet in front of them where the edge of the plant bed is. I probably should not have planted this type of tree there (planted about 6 months ago in ignorance and trees are about 7 feet tall at the moment). I know I am supposed to maintain a pyramidal shape but do I have any chance at keeping these thing off the fence and not growin together? Also the soil is EXTREMELY rocky. Will this limit their growth (hopefully). They are very healthy and very beautiful trees but Im fearful they arent going to be able to stay where I have them, even with pruning. Wish I could send a pic on here.
Yeah, I’m afraid there isn’t a future for your ‘Green Giants’ in that narrow space — even with pruning.
Is there any chance you can change them out to a more narrow growing variety of plant? Since they haven’t been in the ground too long, they would very easily come out?
And if you can’t use them on your property, perhaps the nursery you bought them from could either exchange them or find a buyer for you. For example, a landscape contractor could come into their nursery looking for ‘Green Giants’ and they would have them contact you. Maybe you could even work a deal with the contractor that involves them not only taking the ‘Green Giants’ but installing the new, narrower variety.
Hello, I have 4 Giants on the side of my yard, I made a critical mistake of putting up a privacy screen on my fence and the bottom back half of the trees look dead. i removed the privacy screen with the hopes that the bottom half of the trees comes back to life. Is it wishful thinking on my part?
It’s hard to give an opinion without seeing the plants. That’s a classic scenario you’re describing where plantings too close to fences and other structures defoliate in the back.
It’s possible that some growth originating in nearby live stems and branches could begin to push growth into that bare space. It would help if you’re pruning the plant annually. This would help stimulate growth from within the plant and from lateral stems and buds.
After one year (this time next year) you can (and should) begin to prune out the obvious deadwood, i.e. bare branches that are not showing any signs of budding. At the very least this pruning out of deadwood will improve the appearance and let more air and light into the space.
How far from a privacy fence should Green Giants be planted? I have 5 to plant and get differing advice when googling. Also how much shade can they handle? Its full sun nov- apr but neighbors large decid trees provide some shade in summer.
To be reasonable, I’d space the ‘Green Giants’ 5-6′ from the fence, i.e. from the center of the plant to the fence. Arborvitae ‘Green Giant’ will want to get 12-18′ wide at maturity.
I’ve used them in similar situations of shade as you describe and they’ve done OK. Perhaps they’re a little less full than if grown in more light.
Have 1 20ft Green Giant,Can I not top it off at 14ft.? Or will it look not right ? Almost 4-5ft. wide.
Green Giants do get that elongated leader at the top — they just want to grow taller as fast as they can. 🙂
Removing 6′ from a 20′ plant seems too much to me. Without seeing it, I’d say possibly 2-3′ is more appropriate.
I have some arborvitaes that are very thin in some spots, mainly near the ground. I just purchased them last fall. Can I do anything to encourage growth in those areas?
It’s not unusual to have thinner growth on new plants, and it can be for several reasons. But if the general plant is healthy and the environment/conditions it’s planted in are favorable, i.e. “right plant in the right spot,” it should eventually fill in in those areas.
I always tell new planting owners to allow 2 years for a new plant to establish and assume normal growth. So patience is needed. Remember, this is a young plant and has a lot of growing to do. 🙂
As far as encouraging growth in those weak areas — there really isn’t anything you can do specifically for that. But I would just practice good care. Feed the plants once/year with a general, organic plant food like Plant-tone. Also, lightly prune or trim the upper portion of the plant (once/year) and avoid trimming where it’s weak. In my article “How To Prune Boxwood” I show a sketch illustrating to always trim plants so that they’re wider at the base. This is a key point especially for plants that are weak and thin towards the bottom.
I have a row of Arbs which were present when I bought my house 14 years ago. They are now a nuisance to my gutters. I don’t want to give up the “natural” fence between my neighbor and I, as their lawn care leaves much to be desired. would it be okay to trim them from about 15-20 down to 10ft? transplanting isn’t an option, since there is a gas line and sump pump line within 3ft of the base of the trunks for about 75% of the length of the row.
Also, I have another row which is encroaching on my driveway on the other side of my property. I am contemplating removal of those trees as they are 20 ft tall as well and trimming them back at this point will leave them quite bare on the southern side. how deep does the root structure go if I were to decide to do this, or how aggressive can I be in trimming them back from the driveway? I would likely need to cut out about half of the radius on that side.
As you’re suspecting, cutting the Arbs down from 15-20′ to 10′ is pretty extreme. I’d have to see them to give real guidance on how much to cut.
The plants will survive the cut, but the uncertainty is how they’ll respond and look at the top where they’re cut. The Arbs naturally want to have a central leader that grows in height. You’re proposing cutting that back a lot and then essentially maintaining it there — for as long as you can anyway.
I suspect the side branches just below your cut will push out growth (during the next growing season) and you can begin to “round-off” that top growth to keep the plant from getting taller.
Please keep in mind this is just my opinion, and I have no way of being sure how your plants will react to severe cuts like this.
I realized I did not comment on the second question you had regarding the Arbs along your driveway.
Cutting half the radius of the plant’s branching would look terrible and likely not recover — at least to an acceptable appearance.
The roots on an Arb that tall are approximately 24-30″ deep. And just like you’re aware of underground utilities with the others, I’m sure you’re considering the same with these. Also, I’m sure you’re taking into consideration the impact on the driveway. Loosening the base material (of the driveway) near the edges should be avoided if possible. You might have to do some preliminary “hand digging and root cutting” before you pull the stumps.
Can I keep arbs at 15ft tall? I don’t have much space between my property and next door..any advice?
Over time it will be difficult to contain ‘Green Giants’ to that size. And not just in terms of height, but width too.
You can put up a good fight by diligent pruning and probably get a good number of years of use out of the plant.
There are also what are called “Plant Growth Regualtors“. These products get administered to the plant and control their growth. I have no personal experience with them.
And, of course, if practical and cost effective, you could transplant the plant and replace with something more appropriate for that spot.
What trimming technique could be used so that the top 3rd of the tree could become more full so that there is less gap between the trees? Thanks!
If you follow my advice in the article, i.e. to concentrate trimming in that top third of each plant, they’ll fill in nicely.
Make sure you prune back the terminal leader (main vertical stem) because this dominant stem wants to get taller each year. You’ll have to allow the plant to attain some degree of its height, but in the meantime you’re controlling the rate of the top growth and encouraging a fuller plant.
planted 3-4ft Green Gaints about 5 years ago…didn’t know about pruning doube leaders out so now I hav a lot in my row of 20 trees that are touching now and about 6-7 high…it it ok to prune the double leaders now?
Of course I’d feel more confident giving advice on whether or not to prune out double leaders if I could see the plants.
But here are my thoughts. With your Arbs at 6-7′ tall you could still remove one of the double leaders and the plant would have plenty of future growth to adjust.
Where on the plants (in terms of height) is the double leader occurring? Upper half? Below halfway point?
Again, I’d like to see the plants to guide you more assuredly. Can you visualize how the plant(s) will look right after removing one of the leaders? Can you carefully pull the one leader you’d remove slightly away from the other to give yourself a view of how it might look?
I’ll leave you with this point in the event you decide to leave the double leaders. When we install Arborvitae that characteristically have multiple stems (e.g. Arb. ‘Emerald Green’), we automatically put a supportive band of ArborTie inside the plant 1/4 of the way down from the top. This prevents the stems from splaying apart due to age, wind or ice & snow. You could do the same with your ‘Green Giants’. If you do this, you must remember to monitor those “ties” at least once/year. They will need to be moved and/or adjusted every now and then. This is very important!
I have a single arborvitae next to my front door that has grown to more than 15 feet. This winter the deer have climbed on my front porch to nibble away at it leaving the porch side looking very shabby to about 4 feet high. Otherwise, it is in good health. However, it is starting to dominate the house facade and I would like to trim it to give some space around it. Can I trim it to the trunk from the base to about four feet? And then top it off a bit? I admit it will probably look odd, but perhaps more interesting and shaped. I wouldn’t mind removing it, but it is growing in the corner where the porch and foundation meet, and it would be a challenge to get out of there. Also, is this the best time of year to trim it? Your advice is greatly appreciated.
Pruning up from the bottom to raise the canopy 4′ is an option. We have done that in certain circumstances and with several different types of plants. It should look OK with Arborvitae ‘Green Giant’.
And you can also start pruning the top to slow down the growth. But realize this plant wants to get considerably larger. I’m afraid eventually it will overpower the space. Your diligent pruning will extend the time before that happens.
Now would be a good time to do this pruning.
I’m very new to gardening and I planted some Emerald Arborvitae in front of my house last year in Staten Island, NY. The center of one began to brown and look dried up by the end of the summer. Then the snow this winter damaged some of the branching. Can all of this be fixed? If so, what do I do? I have no clue how to garden and I really want to learn. Thank you so much!
Firstly, did you read my article on ‘Emerald Green’ Arborvitae? It will give you a quick overview of the plant and its care.
The browning in the interior of the plant is normal. It sheds older, interior foliage as the plant matures. Browning on the exterior can be a concern.
They prefer a moist (not wet) well-drained soil.
Also, in the article I referenced above I mention using Arbor Tie to help prevent the splaying apart of branches.
Realize too that plants usually look their worst this time of year — after the winter. In May you’ll get a better representation of how they’re doing.
Hi Roger, great read. My Arbs are probably 20 years old and have dead zones at the bottom 4′. There were overgrown burning bushes in front that created the problem. I’ve since trimmed the bushes. Will these trees fill back now that lights gets to these dead zones?
It’s hard to say if the lower foliage will come back. I have seen new growth emerge in situations like this. It’s good you’ve removed the competing burning bush.
The majority of the bare stems and branches are probably deadwood at this point. But I would allow a full year for the plant(s) to show where and if any new budding occurs. Then, next year you can clearly see where there’s life and safely prune out the deadwood (to the points where it’s live).
Thanks for the info. I read the articles you mentioned and they were helpful. I have one more question…do you recommend a specific fertilizer or mulch? Thanks again!
I’m not a fan of regimented fertilizing. More often plants are being fed that don’t need it. A soil test should be the determining factor, but few people (and “professionals”) rarely do that.
If you’d like to fertilize the Arbs, I’d use Espoma Plant-tone. It will supply general nutrients safely and condition the soil (to some degree) as well.
Mulching would be helpful too. Just be careful how much mulch you apply.
I have green giants (planted about 5 years ago and are now about 15′ tall) that need pruning. Last year I cut about a foot off of the top leader branch. This year I would like to prune the rest of the tree. When and how is the best way. I reading that anywhere from late winter to early summer is ok, but I’d like to narrow it down a bit more. Also, how much of the branch should I take off?
I’d avoid late summer into fall as you don’t want to stimulate any new growth at that time.
You could prune now (spring) and the plant will have the season then to grow & respond to your pruning.
If you like the softer look of the plant, you’ll want to “selectively prune,” i.e. prune back individual branches. This technique will help maintain that informal look while controlling the size of the plant.
You could shear the plant (many people do), but that will give a bit more deliberate shape to the plant. If you do decide to shear, do that now (spring) and the new growth that follows will help soften the look a bit.
I have several green giant trees planted on top of a retaining wall for privacy. They are 2 years old and about 12 feet tall. I cut the leader branch off a couple of them by approx. 12 inches to encourage the trees to grow wider versus taller. Since I cut the tip, will they get any taller or remain approx. 11ft forever?
They’ll continue to grow towards their mature size. It’s in their DNA.
Pruning does slow that down somewhat, and encourage fuller growth.
I have several green giants. Most look ok but would like to prune (just scared to) and 2 look horrible from the winter. Hardly any leaves. Can pruning bring these back?
Hi Roger- we live in Long Island, NY and have 15+ green giants that are approximately 15ft tall, that we would like to have pruned. The landscaper we hired suggested topping them off 4ft however we are afraid they will not grow back in the nice shape they are now. We suggested 2-3ft instead. Would they grow back even when the leader branch is cut? And is now a good time or should we wait until Nov/Dec? Our neighbors are complaining that the sides are overflowing into their space and so we are trying to maintain them now.
Cutting 4′ off the top of a 15′ arb is a bit extreme. 2′ would be enough in my opinion. You could then prune the surrounding and lower branches to begin to taper the shape back to “conical”.
Whenever you cut that much of the leader, whether it’s 2′ or 4′, the plant no longer has a leader. Instinctively it will try to establish another dominant stem to take the lead. Since you’re trying to “stunt” the plant and not let it get too much taller, (a difficult task I might add) you will from this point on concentrate annual pruning at the top to continue the “stunting” effort.
Likewise, you’ll have to be diligent with pruning on the sides to try and keep the plant contained.
You can prune now.
I made a big mistake and cut the main leader too short in our 5′-6′ green giants. The leader has now stopped growing in about 5 of the trees. 2 or 3 side leaders has started to grow. Should I cut all but one new side leader or leave the tree alone. The one good thing is the trees did get fuller but does not have the pyramid shape.
You’re exactly right in selecting one of the stronger shoots and allowing that one to dominate. Simply remove or prune back the others to suppress dominance and restore the pyramidal shape.
I’ll bet they’ll be fine. You say they’re otherwise healthy — and if so, these plants will quickly want to resume their natural growth, i.e. single-stem pyramidal.
I planted some green giant arborvitaes last year. They grew fine all summer. They are only about 1 1/2 feet tall. This spring they are brown. Will they turn green?
If they’re completely brown it’s likely they’re dead. You can scratch the stems and see if there’s any green, but I doubt it.
We just planted a long row of green giants. Some are about three feet tall and have no apparent central leader. Do we need to do something to encourage a leader?
There are certainly ‘Green Giants’ out there with more than one central leader, but it’s better for the plant (long-term) to have one central leader.
Since your plants are only 3′ tall it’s still possible to select the strongest leader and prune out the other(s). Yes, it’s likely to look drastic at first, but they’re so young they’ll have no trouble recovering.
Thank you so much for the articles. I recently started a small tree farm with my first specimens being 400 green giants. I read in one of the earlier replies that you recommend mulch. I have access to rough chopped hardwood mulch. I have read in other forums to mulch about four inches keeping it somewhat away from the trunk. What are your thoughts? Thanks in advance for your reply.
Mulching would be a great idea for the ‘Green Giants’. Just make sure the mulch you’re getting has aged properly.
Here’s an article on mulch with some more helpful points. In the article I say 2 to 3 inches. In your nursery situation you could lean more towards a “heavy 3 inches,” but take care near the base and trunk of the plants. (See article)
We recently had 5 Green Giants planted, close to 7′ tall each. Each tree has a central leader at the top of the tree. But in the case of one tree, there is a secondary trunk. It has been pruned back, but this trunk is pretty thick and looks like it goes all the way down into the ground/root ball. I think it would be good for the tree’s health and looks to have a single trunk with single leader. Would you recommend cutting off this secondary trunk at the ground?
There’s also another tree that is quite full at the bottom, but again, it looks like there are numerous trunks (maybe five or so fairly thick ones) coming from the ground or maybe right above the ground in this case. Should I try to cut these away over time leaving just a single central trunk? Thanks for the help.
There’s no question a single leader is more desirable for ‘Green Giants’.
What makes the decision to remove some (leaders) to retain “one” a bit challenging is the current size of your plant(s). And not from a plant health standpoint, because the plant will ultimately recover, but from an aesthetic standpoint.
At 7′ tall you will probably notice a drastic change in appearance once you’ve done the corrective pruning — especially as compared to the others.
If you do prune out the undesirable stems/leaders, make your cut(s) close to where the stems/trunks come together (at the base). And the cut should be at a slight angle — not straight across. Also, be extra careful not to cut into the nearby stem/trunk.
Hi Roger, looks like you’ve answered similar questions so far but I want to be sure as to not hurt my trees.
I have 3 out 4 large (10-12 ft) thujas with second trunks. The trees are still fairly full when I pull back the smaller trunks on them so astethically they
will be fine and they appear to still be growing right now here in Virginia.
Of the 3 trees, almost all fo them have a second trunk that is only a few inches to maybe a foot shorter than the main one or tallest one.
Do you think it is ok for me to properly remove those second trunks at this time?
If the arbs are ‘Green Giants’ then ideally they should be single-trunk plants.
If you feel that aesthetically the look after removing the weaker leader will be OK, then by all means go ahead. And, of course, the plant will ultimately fill out and develop as it should.
As I’ve mentioned to others, be careful when cutting that you don’t scar the other stem/trunk. And cut on a slight angle if possible.
I have 11 western arborvitae that we planted about 6 years ago. Some get full sun and some are more shaded. The 3 that get the most sun and are the tallest recently started to look thin. It appears as though the needles on a lot of the middle branches on the inside of these 3 trees are falling off, while the ends are green and plush and show some green shoots. It’s been a very dry summer here, so I’m wondering if they could be just dry or are are growing so high that they are starting to thin out? Any advice would appreciated!
The fact that the outer foliage is green and the interior is thinning could indicate the plant is dry (or drier than those in the shade).
I’d begin a watering schedule of sorts, particularly for the 3 in full sun — but I’d include the others as well. Deep soaking waterings are best. So first wet the soil beneath the plants so it “accepts” the watering and the water does not run off. Then place the open end hose at the base (of each plant) and allow the hose to run at a slow trickle for a length of time — perhaps 40 minutes to one hour. (A soaker hose is an option as well) Maybe do this once or twice a week during the hot, dry months. Don’t let them go into the late fall and winter dry either.
Being on the conservative side, I’d hold off pruning the larger 3 Arbs for this season. Let the plants recover this season and then prune them next year so they fill out a bit.
I have 12-14′ arborvitia’s bordering my property line in the back yard. Unfortunately i need to put up a 6′ fence to keep my dogs in the back yard and off a leash. I need to cut in about a half foot on one side of the bush and trim 6 feet from the bottom up. To make room for the fence about 40′ down the property line. There are a few spots where thick branches will need cut back. By doing this will it kill the entire arborvitae. I dont care if its dead against the fence, since no one could see. Just worried about the lush green on the yard side. I plan on paying a lawncare company to do this. They appear very health and beautiful. Its a shame we have to butcher it that bad on one side. But it is necessary for the fence line. Any thoughts would be appreciated. Thanks
You’re right in that the side against the fence will be gone, but that does not necessarily affect the look and health of the rest of the plant. Therefore, prune what you have to for the fence install.
It’s hard to give exact advice w/o being there and seeing the situation. But on the backside, where the fence is going, that foliage will likely brown and die — we see this all the time.
Can Green Giants be trimmed into a formal hedge shape like the red cedars can?
It’s certainly possible to trim/shear Green Giants, but keep in mind that this plant aspires to grow quite large… and quickly. This will make it more of a challenge to keep the plant/hedge within a manageable size for a long period of time.
I have what I believe is a Green Giant it’s 25 foot tall 7 foot across, it’s over grown the spot its in.
The plant was a Arbor Day sapling our son planted 24
years ago. My question is how do I go about starting a
new plant off of the one i have.
Any advice you can give would be appreciated.
I’m not sure your plant is a ‘Green Giant’. The fact that it’s only 7′ wide at 25′ tall is not characteristic of ‘GG’.
Regardless, it’s quite challenging to propagate woody plants like arborvitae. My last experience with plant propagation was in college — and that was 40 years ago! 🙂 But I looked up specifically the details of propagating ‘GG’ and here are the details.
PROPAGATION for Arborvitae ‘Green Giant’: Dormant seed lots have been encountered occasionally on which stratification in a moist medium at 34 to 41°F for 30 to 60 days stimulated prompt germination (variation among seed lots). Cuttings rooted well when taken in January. Best to collect cuttings after cold weather has set in. Raulston mentioned 95% rooting on December–January cuttings with 8000 ppm IBA talc and mist. With 25 clones that I collected, rooting averaged 88% when treated with 5000 ppm KIBA, 3 perlite:1 peat, bottom heat (70°F), and mist.
Your best bet would be to find a supplier of “arborvitae liners”. These would be very young, rooted plants that are inexpensive. You can then plant them out in your yard or field — or even grow them on in pots for a couple of years. Try and “Google it” and I’m sure you’ll find suppliers/growers.
I have a row of 30 green giants planted on 4′ centers as a privacy screen. They started as 5 1/2′ trees and many are now approaching 20 feet after 8 years. They are 10′ at the base. They get full sun and are very healthy. They have grown pretty tightly together and are super healthy. I think that 5 more feet of height is as tall as I’d like them to get. Should I be worried that their being so close together may begin to take a toll on them? If so is there a pruning strategy I should consider for their height and width? They really are spectacular. Thanks!
Your ‘Green Giants’ are keeping to their name. 🙂
I’m glad they’re doing so well, but you’ll have a challenge to keep their height in check. I would begin pruning the tops to slow the plant down and also realize, from a practical sense, how tall you’re able to reach and maintain them.
With regard to their 4′ spacing, it would have been better to have more space between them, but they should be able to coexist as a hedge with this spacing.
There really is nothing to do (pruning or otherwise) to address this spacing. Transplanting is probably not an option because at this stage they’re likely grown together as a hedge. And already the growth between them has died off and become bare. Therefore, continue to maintain them as this “unit/hedge,” i.e. prune the sides and tops to keep them within bounds — as best as possible.
Thanks Roger. They look very healthy and happy. My wife says don’t mess with success and leave them alone. Can I trim the sides vertically to make them more “hedge-like?” If so, when during the year?
Also I’m about to put in another row elsewhere for screening again. I’m thinking to use 5′ centers this time. Is there any way to keep them to 12 – 15′ height? Thanks!
I would prune the sides and top if you want to preserve the plants long-term. Without pruning they’ll continue to get larger — aspiring to their mature size. Again, they don’t call them ‘Green Giants’ for nothing. 🙂
Prune/trim them as a hedge, i.e. don’t try to separate and treat them as individual plants. On the sides (front & back of hedge) prune/trim so the plant is slightly wider at the base and tapering towards the top. Not only does this look correct, but it’s how the plant naturally wants to develop.
I would prune the overall plants in the spring. There are stored foods in the current growth that the plant will utilize through the fall and winter. Next spring you can safely prune as the plant begins its new cycle.
In the long-term it will be difficult to keep these plants 12-15′ in height. Diligent pruning will extend the time you can keep them at that height.
Hi Roger…its been almost a year since i posted my question. Fast forward my arbs are doing great. They will be 3yrs old next spring. They are 6ft tall. When should i give them their first haircut? Lol. Thanks
It’s never too early to start pruning ‘Green Giants,’ especially if you have any plans of maintaining the plant within certain bounds.
You could prune in early spring.
So i should wait till spring?
I would wait until spring. It’s healthier for the plant, and no real advantage to pruning now.
Can the green giant be pruned to grow narrower?
You can control the plant’s growth to a certain extent and for a limited time. But eventually the plant’s health and appearance will start to decline because of the harsh pruning.
If you can, transplant the ‘Green Giant’ to a more open space and select a narrower growing variety such as: Arb. ‘Wintergreen’ or Arb. ‘Steeplechase’.
I have green giants that are about 4.5 feet tall (planted last spring, although they are growing well, there were damaged branches about 2/3 of the way up which has left a section of nearly a foot that is “bare” all the way around. Howevedr the top and lower half is doing well, but I can’t bear the bare spots, should I top them off? Can they be spliced with a growing shoot? any ideas?
At 4.5′ your green giants are very young, so they have tremendous capability to recover.
I would not top them, but simply prune/trim like I show and describe in the article. By just tipping the ends of branches as you shape the plant, you’ll encourage lateral growth which will fill in those empty spaces.
Alright then, that’s the plan. Thanks so much for the reply.
I have a staggered row of 10 giant arborvitae that are growing really well. I got them at 8-ft a few years ago and they are already a good 11-ft tall. I really want them wide at the bottom to create a green wall with neighbor. Should I still prune them to keep them fuller, or let them keep filling out? Do I risk them getting leggy if I do t prune them?
Yes, you’ll want to keep lightly pruning to encourage a fuller stronger plant. Eventually, it will likely become impractical (if not impossible) to prune — but at that point you’ll have nice, full, strong trees.
Remember, even just trimming the tips of branches removes the end (apical) bud, which then allows lower, side growth to develop.
I have 2 giant arbs in front of my house, each on one end of the house. When I got them, I had no idea they would get so big! Is there any way to dig them up and relocate them to another part of my property. They are really healthy but they are beginning to become hard to mow around and they are creating an environment for algae on my siding. Thank you for your kind help. Tina Uebler
To really give advice on whether your arborvitae can be transplanted I’d have to see the situation. Variables such as: access, proximity to the house, other plants and other structures, etc. come into play.
Plants of all types and sizes are transplanted regularly, but all the variables have to be considered. And at that, even when transplanting is possible, the cost has to be considered. Sometimes the cost exceeds the value of the plant.
I would suggest getting a few opinions and estimates from “experienced” plants-people in your area. On this page on my website are articles with more information on transplanting.
Roger, thank you for your article! I planted 30 of 9-10ft ones 2 weeks ago and I planted them in a row 3 ft apart and 2-3 ft from my fresh poured concrete driveway. Besides, there is a gas pipe 4-5 ft below them. Unfortunately, I didn’t do my research before I’ve planted them and didn’t realize they are going to become so huge in a while.
My concern is that I placed them way too close to my driveway and that the gas pipe beneath. Besides, my initial plan was to keep them no higher than 15-20ft but I didn’t realize what I was buying 🙁
Options I think about are:
1 . Remove them and plant something else (don’t really like the idea for many reasons)
2. Move them further from the driveway(max. I can move them is 4 ft from the concrete edge) but that gas pipe is still beneath. Also, I can space them 4 ft apart to give them more space to grow.
3. Leave them as is and keep pruning them to make sure they don’t grow bigger than 15×6 ft wall
and, hopefully, it will keep the roots from spreading that much to damage the driveway and the pipe.
here it is the youtube link to show how it all looks at the moment
thank you for your advice!
Based on what you’ve written and the YT video, I would work along the lines of your #2 option, including changing/increasing the spacing to 4′ apart. You’ll still need to diligently monitor and prune the ‘Green Giants’ to keep them within bounds (both height & width).
If the gas line is 4-5 ft down, you should be OK.
I have 20 green giants planted along a fence line. We planted them 4 ft apart and 4ft off the fence about three years ago. They are spot 6 ft tall as of now. As instructed by the nursery, we have been trimming the leader in early spring to encourage a fuller tree.
We are hoping to maintain a thick square green wall with these trees. Will we be able to keep pruning the top and sides to shape them?
Would you advise not cutting the leader next year to encourage the top to grow and not so much the sides?
Green Giant, as you know, has the ability to get large fast. You’ll need to continue to keep this plant under control by pruning — including the top leader. You’ll still be able to allow it to grow each year (to your vision) even though you’re pruning it to keep it “in-check”.
You have an advantage here in that you are aware of its potential. Most folks either are not aware or simply don’t pay attention — at which point the plant outgrows the space.
Hi! My neighbor planted 40 of these 1′ off our property line; despite my attempt to educate them about the ultimate size of these….. Anyway, they’ve reached about 7′ high and encroached onto my side by 3 feet at this point (no surprise). How do you suggest I prune these monsters – shearing or further down the branch? And we are considering a privacy fence to push back the growth (150′ of pruning is not in my annual plans) but will they take out the fence – their side is the sun side…. Thanks!
This kind of thing happens a lot. And if yard space is “precious,” you’ll want to do everything you can from day one to preserve it.
The fence is a good idea. Keep in mind that fences with wood posts eventually rot where the posts meet the ground. This will allow any pressure from the growing arborvitae to push over the fence. Ideally you want to choose a fence (or a least the posts) that do not rot.
Also, realize that the fence will help contain the arborvitae to the height of the fence. After that the plant’s growth will continue over on to your property.
I think your best course of action is to go with a strong fence, and then an annual trimming regimen that “shears” the arborvitae back to the fence line. Notice I said “shear,” not prune. It’s unrealistic to think you could selectively prune all these arborvitae. The key here is to start early on, before they really encroach over the fence.
The tools to consider would be a power trimmer and/or a telescopic power trimmer.
I planted 40 green giants on my property to have a live fence in May 2016
Unfortunately a few of these thinned out at bottom even though the trees were strong and healthy.
This summer even after all the new growth they put out, the lower part of these trees did not thicken out much. My trees were 6 feet tall last year and this year they added aroud 3 to 4 feet.
I read on internet that cutting back on central leader and top growth areas will encourage a tree to thicken out at bottom. As a result I cut back the central leader by around a feet but now I am worried that I have damaged the tree because of this. Will I have to now train a branch to become central leader? If yes, will this not structurally damage the tree as the trunk for ever will be a little rounded instead of being straight?
The trees are healthy overall and get full sun. I am in NJ zone 7A.
If you removed only one foot of the leader you should be fine. The arborvitae should continue to grow with one, strong central leader.
Overall this is a good strategy to encourage a fuller plant. And since the lower portion of the plants are weaker, this is really the solution to improving that.
Thank you so much for the information.
I cut down the central leader of green giant arborvitae that were growing too tall. Does that mean they will no longer grow from the middle where cut? I feel i may have made a mistake.
How the plant(s) will grow after your pruning depends on how much of the central leader you cut. If you cut a minimal amount, such as 6″ or so, the plant will continue to grow with “that” central leader. If you’ve cut a considerable amount (and it’s hard to say what that is w/o seeing the plants) then the arborvitae will have several, top lateral branches that will push growth out their ends. In this case, and if you want to re-establish a central leader, you’ll need to do some selective pruning to gradually encourage one of those top, lateral branches to assume the role of central leader.
Hello. I live on a pie shop lot my neighbor has the same. I planted 25 emerald green arboro 5 years ago on a fence line that did not do well in the back of our property for privacy. We both agreed to rip them out and replace with green giants. Placing then 5 ft apart I come up with 12 needed to plant
I am worried about the size the giant will get down the road. Area is tight. Is it better to plant 6 on my side and stager 6 on their side evenly spaced to control size better ? Or plant them on my side in a straight line as my emerald greens are now . I am more worried about width
Planting 6 on your side and 6 on your neighbor’s (staggered) is better for the plants, but the 6 on your side will ultimately take up the space you’re concerned about. Can you plant right on the property line? I’ve had homeowners do that — and often they’re splitting the cost of the planting too.
I have 6 green giant arborvitaes , they are about 20 tall, another 5 ft they will be in a power line. How far down can I cut off the tops? They are all nice and full all around except for the top 2ft or so? Then do I cut every year or 2?
It’s hard to say exactly how much to cut back the leader, but I’d say cut back to where the plant(s) are fuller with growth. So perhaps that’s 2-3′ or so.
And you’re correct in the need to prune consistently to “stunt” the plant’s height. You’re definitely attempting to stop the plant from doing what it naturally wants to do.
The good news is you’re aware “now,” and are taking the steps to control the height.
As far as a schedule goes, I would say to monitor the plant’s growth and plan on pruning at least once/year. Essentially you’re removing the central-leader of the plant. So now, instead of having one dominant central-leader, you’ll have a rounded or domed top — like a rounded shrub would have.
Hello, we just installed a vinyl privacy fence and want to plant Green Giants in front of it (inside our backyard). How far from the fence should we plant? We don’t have too big of a yard so want them as close as possible to the fence. Also, we border a busy road and a business so we want as tall and thick coverage as possible, how far apart do you recommend we plant them? I’ve seen advice ranging from 4 – 8 ft
Green Giants do get fairly wide (approx. 8’+). If possible, I’d plant 4-5′ from the fence, i.e. the center of the plant to the fence.
In terms of spacing, if I have the room and planting larger plants, e.g. 8-10′ high, I’ll space them around 8′ center-to-center. If your plants are smaller (and you’re anxious for a screen) you could go to 6′ center-to-center. They’ll grow together, but should coexist.
We are planting the green giants on our property line for privacy, windbreak.
There used to be black walnut there. Will that harm them? And should I space them 5’apart,center to center?
Green Giant is a great choice for a border plant. And you should be fine regarding the black walnut that was there. Arborvitae is tolerant of its toxicity. I refer to this list from the Morton Arboretum for plants susceptible and tolerant to black walnut toxicity.
As far as spacing on the arbs, I would not go closer than 5′ apart (center-on-center). And if you’re able to I’d go further apart. I’ll often space them 7′ C-C on a border. This to me is a nice compromise between not too close and not too far apart.
I have a corner lot and initially I planned to space 18 Green Giants 8′ apart for a border, but in the local nursery they say I should consider spacing them 15′ apart. This distance seems to be too large. What is the optimal spacing considering screening ability and the overall health of the trees 10 or more years down the road? The trees will be under full sun most of the day in zone 7a. Would 10′ apart be a good compromise? Based on the reading in this nice post, I assume iI would need to trim the trees every year by 1/3 of the top 1/5 part in oder to make them full at the bottom. Thank you. Slava
Doing your research is so smart on this matter. Appreciating mature plant size and spacing correctly will pay dividends in the long-term.
8′ center-to-center spacing is one I use frequently for Arb. ‘Green Giants’. I’m often driven by the client’s request for privacy. So, in this instance, 8′ centers gets you there relatively quickly, but still respects the health and development of the plant. Yes they’ll definitely join, but should coexist in the future.
15′ spacing is certainly nice as the plant will have plenty of room to develop over the years, and eventually touch one another.
I do like your compromising spacing of 10′. If you can use that, I’d go with it. 🙂
And yes, the upper pruning/trimming I recommend in the post would be great. I think this project is going to turn out great!
I have a couple questions,1. My giants came balled and burlapped,should I remove the burlap? Any planting advise? They will have sun all day.
After the plants are set in the hole and positioned exactly how you want, backfill just enough at the base of the ball to stabilize the plant. Then you can carefully cut and remove the upper portion of burlap. If there’s a wire basket on the ball we try to remove as much of that as possible too — again, after the plant is positioned and stabilized in the hole.
We just purchased our first home and we have a nice wall of arborvitaes the previous owner planted. Most of them are of different heights, the tallest one being about 18-19′ tall. My goal is to get them all at about 17-18′ tall. There about 3 that are over that mark, and the rest are under that.
My questions are:
Will trimming the trees (at the top) that are under my goal of 17′ encourage them to grow taller? Or am I better off leaving them alone and letting them reach 17′ on their own?
Taking a foot off the tallest tree to get it to 17′ should be no problem right?
Below is a link to some of the trees. For reference, the orchard ladder is 16′ tall.
Thanks for you help!
You should be able to maintain the arborvitae in the 17′ height with annual pruning.
I would not say that pruning the smaller ones will encourage growth. I think you can just monitor them as they grow to the desired height.
And taking one foot off the taller ones is fine.
It’s good you have the 16′ orchard ladder for this. 🙂
Thanks for the quick reply, Roger!
I will leave all the trees shorter than 17′ alone and prune the trees taller than 17′, to 17′.
In the meantime I will prune the sides of all the trees to keep them the same thickness and encourage density.
How are your skills when it comes to determining the different types of arborvitaes? I ask because the ones in my driveway are lighter/more vibrant green than the ones in the picture I linked. If i were to take a close up of them side by side do you think you could determine which species they are?
I was fortunate with the orchard ladder; I looked at them brand new and they were $500 and up but got lucky and found that one on craigslist for $240!
Again, thanks for your help!
It can be difficult to identify arborvitae varieties. If you want to post a link like you did the last time with a picture of it, I’ll give it a shot.
Based on the above replies it appears the answer is yes, but would I be able to maintain Steeplechase Arborvitaes at 15-20 feet?
I am planning to make a hedge with these but I can’t get a straight answer on their natural size. Most sites say 18-20 feet tall and 8 feet wide but some say up to 35 feet tall which would be way too much!
Thanks in advance.
I don’t think I’ve seen Steeplechase over 25′, but I’d say it’s possible.
You did say “maintain” Steeplechase to 15-20′, and I think that’s entirely possible. It sounds like you’re very aware of your home’s landscape and plantings, so I’m sure you’ll keep an eye on the arborvitae’s development from year to year.
If possible, I would not wait until the plant reaches your desired height and then start controlling it — start earlier. The plant will only benefit from pruning.
I have a space between my house and my neighbor in which I’d like to have green screening to reach the second story of the houses. I’ve been advised to plant Green Giants. There is plenty of room for these trees, but I’m concerned about the light. The space is on the north side of my house with the L-shaped houses on either side of the planting space impacting sun exposure. There are a few hours of direct sun in the summer, but a little less in the winter. How tolerant are these trees of shade? I’ve been told by two landscapers that it isn’t a problem, and two other landscapers said it is a problem – they recommend Nellie Stevens Hollies. I would appreciate your advice.
The Green Giants should do fine. Here I’ve used Green Giant on the north side of a school gymnasium.
It’s been several years and they’re doing beautifully. If anything they’ll get a little less full with less light, but not in a negative way.
Nellie Stevens can be a nice plant too, but I’d say it’s not as “tough” as Green Giant.
I have Thuja Green Giants. I have about 25 of them planted about 5 feet apart. They are currently about 6’ tall. My hope is to have them as a privacy hedge. Should I start trimming the sides this year? I am not concerned with the height but want them to be thick. If I should start trimming can I use a gas trimmer and just trim off an inch or two?
As I mentioned, the tops are where aggressive growth occurs — so you’ll want to trim them lightly to encourage lateral (interior) growth. And it wouldn’t hurt to tip the side growth too. I think a gas trimmer would work fine. Just be careful because the power trimmers can cause one to cut too much. It’s like they have a mind of their own. 🙂
I planted a row of Green Giants last fall – they were 5 feet tall, quite thin, and light green rather than a dark green in color. Now, after a full year of growth they added 2 feet in height, still very thin (never really filled out at all), and never turned the dark lush green that I expected. First question – how to make them fill in without stunting the growth as I want them to continue to get taller. If I prune the main leader will it continue to grow or once a leader is pruned is that particular leader done? Second – any suggestions on the color – light green/yellowish instead of dark green? Any advice would be much appreciated.
Trim them lightly. This removes the apical bud at the end of the branch and tells the plant to direct growth “laterally”. This will make the plant fuller and stronger over time.
As I mentioned in the article, trimming the upper portion of the plant, including the leader, is important with Green Giants because they naturally want to get tall fast. The amount of trimming you’ll do (because you’re trimming conservatively) will not affect the leader.
There could be a number of reasons the color is not dark green, and it could be that it will take more time in “your” soil and environment for them to adjust. Soil make-up has a lot to do with it. A soil sample analysis would give a clear picture on this. I would give them another year or two to establish in your ground. You could always get a soil analysis then if they don’t darken. Foliage color doesn’t always have to indicate a problem or detriment to the plant. If they’re growing well and are generally healthy, that’s the main thing.
I just had some Green Giants planted in my back yard today and I’m wanting to know how to train them to be at a certain height and width if at all possible and also about maintenance. I’m hoping to keep them under 20 feet but yet be full as to maintain privacy. It may help you to know that today is the 17th of November in Charlotte, NC and the trees are about 7 feet to the top and spaced about 7 feet to center as well. I appreciate it!
It’s good you’re looking into ways to control/train the growth of your Green Giants at this early stage.
First off, I think the 7′ spacing is good. They’ll easily touch to form a solid screen for privacy. You mentioned controlling the width so I’m presuming you have limits, perhaps on both your side and your neighbor’s, as to how far the arbs can grow out. In my experience Green Giant wants to get 15-20′ wide. Thinking realistically and in the long-term, you should probably anticipate the arbs extending 6′ (from center) — even with trimming.
In terms of height I think keeping them under 20′ is possible with a trimming/pruning regimen. Think about the tools and ladders you have (or will buy) to let you maintain this height — or the company you’ll hire to do this for you. I find it can be challenging to find companies that can prune at greater heights.
I would start trimming the tops lightly each year to encourage a fuller and stronger plant. As you begin to reach a height that satisfies the screening you’re looking for, I would begin trimming the tops more aggressively because now you want to slow down the top growth.
Okay cool. By lightly trimming, you mean just a deliberate flat cut at the top right?
Not so much a deliberate flat cut. Check out the “before” and “after” pics of the arb’s top in the article. Unfortunately they’re more silhouettes than detailed pictures, but you can see how I still shaped the top “pyramidal” while reducing the height.
Thank you for this discussion. I just planted four very young green giants in the easement between the sidewalk and the street (about 4′ width)in front of my north facing house. I would like to train them to be bare at the bottom as they grow creating an overhead canopy. Is this feasible, or did I choose the wrong variety?
You can definitely train the Green Giants to develop a canopy that people can walk under. And the trunks are actually quite nice to look at too. 🙂
Since you’re aware at this early stage of your intent to have a raised canopy, you can plan to begin pruning the first (and bottom branches) before the plant is too advanced. What is that time you might ask. It’s a judgement call on your part.
I would let the Green Giant develop as a fully branched plant for a few years. I’m presuming they’re pretty small right now. Trim them a bit annually to encourage fullness and stem strength. Once the plant starts to fill the 4′ space (in terms of width), you could begin to remove some of the lowest branches. I feel like you can do the entire canopy-raise over a number of years (i.e. incrementally), but you’ll have to use your judgement here.
Not to worry. In the end, regardless of your schedule, it will turn out fine.