soaker hoseWhat’s “The Core” And Why Is It Important

When I use the term “core” I’m referring to the center of the plant’s root ball.  A nursery plant that’s been dug, balled & burlapped (B&B) is now totally reliant on that root ball to keep it alive.

One of the major concerns of everyone handling and caring for that plant should be to keep the root ball adequately moist all the way through to its center or “core”.

Here’s why that’s so important.  Undoubtedly all nursery plants will have their “ups and downs” with moisture availability due to varying conditions and circumstances.  Typically the root ball will begin to dry on the exterior.  If moisture is not provided, the dryness will continue towards the center.

If the dryness travels too far into the root ball:

  1. In all likelihood the plant will be severely stressed and damage will occur.
  2. Restoring moisture back “to the center” of the root ball can be slow and difficult.

soaker hoseThe trick is to not let the root ball get to that point.

If you watch and monitor the moisture levels of your nursery plants (whether they’re above ground or planted) :

  • It’s easier to maintain consistent moisture throughout the root ball.  Dry soil can become “hydrophobic,” making it very hard to re-wet.
  • You avoid plant stress that could be irreversible.  Yes plants often bounce back from early stages of dryness, but if the dryness is prolonged and represents drying “to the core” it’s not good.

How To Maintain Moisture Levels

Consistency is the name of the game.  If the nursery plant is being stored above ground, it is that much more challenging because the root ball is exposed to sun & wind.  Whether you’re watering by hand, sprinklers or a drip system designed for nursery stock, be vigilant.

If the tree has been planted, consistency is still key, but being in the ground helps tremendously (no pun intended).  The earth protects the root ball and insulates to help moderate temps. and slow moisture loss.  Still, the plant is losing moisture through its leaves (transpiration) and the soil is gradually draining & drying.

Sprinklers will work  for the most part, but again, consistency is key.  The watering must work its way from the surface down to the “core” of the root ball.  With a steady watering schedule the moisture level should be maintained through all the soil levels.

Sod staple

Sod staples hold pipe to the ground

During these hot summer months in particular, we’ve been using 2 watering methods to ensure our larger, recently installed plants are kept moist “to the core”.

The pictures above show basic, store-bought soaker hose being used.  I’ve coiled a 50′ length around the base of this newly planted tree using sod staples to hold the hose down.

The root ball on this plant is 42″ wide.  It’s imperative this tree stay moist to the center of the root ball.

Every few days the homeowner connects a regular water hose to the soaker and lets it run for just 10 minutes.  We found that this schedule during this hot, dry weather is adequate to keep the root ball moist.

The other method we use is the “Treegator”.  The one in the picture holds 20 gals. of water.  It’s designed with a zipper from top to bottom so you can wrap it around the trunk.



With the Treegator the concept is that the water-bag (or reservoir) be filled with a hose and then allowed to drain gradually by itself.  It can take several hours for the bag to empty.

Both these methods concentrate water directly over the root ball where it can seep in without much “runoff”.

I should mention that it’s equally important to monitor the moisture levels below the ground while these watering methods are being used.  Keeping the plant moist is important, but “over-watering” can have damaging affects on plants.

Irrigation is such an important part of plant health and it seems the least understood.  I’m going to continue to write about it in the hopes that this basic fundamental of plant care is better understood and practiced.

There are so many “tricks of the trade” and techniques for watering.  If you have one I’d love to hear about it in the comments.

  • Mike
    8:26 PM, 31 July 2010

    I still make a well with soil around the ball and fill it with water. Doesn’t anybody do that any more. Good info….keep it up

    • Roger
      9:42 AM, 1 August 2010

      Mike, we still make earth wells around newly planted trees in certain circumstances. And there are other watering methods too for watering newly installed plants. I’m going to do a post on some these in the near future.

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