1.The ideal time to plant a new tree is when it is dormant: after leaf drop or in the spring before the leaf buds break open.
2.Dig a hole a little wider than the tree root ball but only just as deep. The International Society of Arboriculture gives this advice on their web site: “Make the hole wide, as much as three times the diameter of the root ball but only as deep as the root ball. It is important to make the hole wide because the roots on the newly establishing tree must push through surrounding soil in order to establish. On most planting sites in new developments, the existing soils have been compacted and are unsuitable for healthy root growth. Breaking up the soil in a large area around the tree provides the newly emerging roots room to expand into loose soil to hasten establishment.”
3.Remove burlap or other wrappings.
4.Place the tree in the hole so that the root flare and top of the root ball is level with the surrounding soil. (ILLUSTRATION A.)
5.Back fill the hole with the soil that you excavated, tamping in firmly as you go. It is not necessary to amend the soil. In fact, pouring rich soil into the soil creates a “container” effect; the tree roots will tend to stay within the small bowl of soil instead of spreading out and forming a strong, stable base for the mature tree or shrub.
6.Apply a layer of mulch—professional arborists recommend that mulch be only 2-4 inches deep—DO NOT MOUND THE MULCH UP AGAINST THE TRUNK. (ILLUSTRATION B.) This type of “volcano mulching” is harmful to trees: it can starve the roots of oxygen and/or encourage the tender feeder roots to grow up into the mulch (rather than down into the soil) where they dry out quickly and are more susceptible to damage from insects and foot traffic.
7.Create a shallow “well” with the mulch that will help to collect rain water and prevent run off during irrigation.
8.Make sure your newly planted tree receives 1-inch of water per week the first 1-2 years after planting. Don't assume or guess how much it rains. Use a rain gauge and when rain fall is insufficient, place a trickling hose pipe on the root zone for an hour. Monitor the water flow so that it doesn’t wash away mulch or soil.
9.Stake the new tree only if it is an extremely windy site. Research has shown that new trees will grow stronger and establish roots more quickly when not staked.
The International Society of Arboriculture offers provides a wealth of information on their website at www.treesaregood.com, everything from how to buy the right tree, to planting, pruning and proper mulching techniques, and how to locate a local certified tree specialist. You can also contact them at the following:
P.O. Box 3129
Champaign, IL 61826-3129
Click on either illustration to see a larger view