Q: I received some small bare root trees and wonder how to
plant them properly. How deep should the hole be?
cannot tell you exactly how deep to dig the hole for your bare root
trees because it depends on the root mass of each individual tree.
Generally you need a wide, shallow hole because a tree’s root system
will spread wider rather than deeper.
A common misconception is that
a tree’s root system mirrors its top growth. However, many years of
research demonstrates that is not the case. A tree’s root system is
comprised of the larger anchor roots that primarily function to
stabilize the tree in the ground and hold it upright, as well as a
large network of fine feeder roots that are responsible for
absorbing water and nutrients from the soil.
These typically spread
out one to two times the height of tree and are found in the top six
to eighteen inches of soil. Roots need oxygen and adequate moisture,
which are usually found in the same part of the soil profile. One
the most common reasons that trees fail to establish and thrive is
that they are planted too deeply, which deprives them of the
A good rule of thumb is to
plant trees so that the root collar is right at ground level. The
root collar, also known as the trunk flare, is the swelling of the
trunk where it meets the roots. While this is easy to see in a
mature tree, it is also visible in your small seedlings.
Planting Bareroot Trees
When planting bare root trees,
dig the hole deep enough and wide enough so that you can build a
cone of soil in the bottom of the planting hole. Spread the
sapling’s roots evenly over the cone and into the hole so that they
are not bent or curled in any way.
VIDEO: How to plant bareroot
Jamming tree roots into a hole
that is not wide enough often results in circling roots that can
become girdling roots as the tree grows and matures. These are roots
that grow against and into the trunk. As both root and trunk grow in
diameter, the impingement can cut off the flow of water and
nutrients to that side of the tree. In severe cases, a girdling root
can completely encircle the trunk, and tree winds up choking itself
to death. Girdling roots can also make a tree more susceptible to
wind throw. Make sure the root collar sits atop the cone so that it
winds up just at the soil surface.
Girdling root on a Maple
You can create a shallow berm
around the edge of the planting hole so that it catches and holds
water. Water the saplings after planting to settle the soil and
force out any air pockets. Do not place any fertilizer in the
planting holes as it can burn the tender roots when they start to
grow. Hold off until next spring, and fertilize based on soil test