Now, you might think that an entire article dedicated to digging a hole for a tree is a bit much, but think about it: The hole you dig today will be your tree’s home for decades – perhaps even centuries. In 20 or 30 years’ time, an oak sapling with a root ball just 12 inches wide can grow to 70 feet tall and wide. Since most root systems reach out about three times the width of a tree’s crown, that translates to a root system stretching 210 feet in diameter!
Large or small, all trees need a good start, so dig them a good home.
Photo Credit: CREDIT
In addition to a good hole, new trees need at least two seasons of regular watering and good fertilizing for maximum health.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
A key to growing long-lived trees is to start with selections that are well-adapted to your soil type and other site conditions. For example, if you’ve got clay soil, choose something like catalpa, scarlet oak or sassafras (which can thrive in clay soils) instead of something like arborvitae, red oak or white pine (which prefer sandy soils).
Another step to growing a healthy tree is to plant your young tree in soil that’s similar in type and texture to the soil that its entire root system will occupy at maturity. Assume, for example, that you’re planting a shade tree and your site is mostly heavy clay. Unless you plan to amend the entire area – at least 100 feet in every direction – your sapling will do better in the long run if it’s planted in unamended clay soil. Extensive planting research has shown that trees planted with only native soil in the planting hole develop larger, better-established root systems than those planted in holes to which amendments have been added.
In some cases, you may wish to enhance your soil by adding mycorrhizal fungi (organisms that promote tree root development). Most healthy soils contain sufficient amounts of these fungi, but tightly compacted soil that’s been compressed by construction equipment or heavy foot traffic may need supplements. (You can find various mycorrhizal fungi products at your local garden center, as well as online.)
If all the topsoil has been removed from your site (as can happen during the process of building a new home) and only subsoil remains, you may want to bring in a load of fresh topsoil before you plant your trees and shrubs. You can order topsoil from many home improvement stores and garden centers and have it delivered. (The staff can help you calculate the proper amount you’ll need for your site and purposes.)
Now, to dig that planting hole… Gather a shovel, measuring tape and gloves, and take the steps shown in the following pictures and described in their captions. Then take extra good care of your tree for at least the first year or two until it becomes established – and your tree should give you decades of beauty in return.
Dig Tree Hole
Dig Tree Hole - Step 1
Measure the root ball’s height from its base to the soil surface. This should be the depth of the planting hole. Measure the root ball’s diameter to determine the hole’s width, which should be 2-4 inches wider than the container (or root ball).
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Dig Tree Hole - Step 2
Dig the planting hole, setting excavated soil at least 3 feet away from the hole’s edge. (You’ll need full access to the hole later when you position the tree.)
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Dig Tree Hole - Step 3
If your planting adjoins a path, driveway or other structure, install barrier fabric or sheet plastic around the hole at the ground’s surface to guard against surface roots. (That said, if you’re planting certain trees that have large surface roots, lanscape fabric will not prevent them! Shallow-rooted, invasive trees can lift pavement and increase the effort needed to mow beneath them. It’s best to carefully choose plants that will avoid such future challenges.)
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Dig Tree Hole - Step 4
In arid climates or those with sandy, fast-draining soils, install a deep-watering tube of perforated PVC pipe at the edge of the planting hole. Block its end with a PVC cap and wrap the pipe with landscape fabric for installation, then fill it with gravel or cap its top end to keep it free of debris.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
