Planning and Planting
When planting trees, the goal is to create an environment that will allow the roots to spread wide in their youth, both for stability and drought tolerance. If planted in late autumn or early winter, trees naturally receive an ideal growing environment (i.e., one that is cool and moist) for their first four to eight months.
Prepare a planting area that is no deep-er than the tree’s existing roots, and that is two to three times as wide. Digging a hole too deep (sometimes called a “tree grave” by experts) can cause the tree to sink below grade—a common cause of tree mortality. The correct planting depth can be determined by gently removing excess soil from the trunk to expose the root collar (the point where the flare of the trunk is widest and the uppermost root begins), which should be level with the soil’s surface.
If the tree is in a container, remove the pot, gently untangle the roots, and slice any circling roots with sharp clippers. If the tree is balled and burlapped (B&B), settle it so that it’s level. It is very important to avoid planting the tree too deeply, as it is difficult to raise it once planted. Remove any wire caging, twine, or burlap by snipping it away with scissors. (It’s OK if a bit of burlap remains attached to the roots, as long as it’s made of all-natural fiber.) Once in the ground, no burlap should touch the trunk or approach the soil surface.
Position the tree, spread out the roots, and backfill with the native soil. If you are planting in construction backfill or soil that is poor or compacted, select a tree that is tolerant of poor soil, like the Cornelian cherry dogwood. Mix in a couple of spadefulls of fine, wood-based compost ($7 per 1.5 cubic feet at Cornell Farm, cornellfarms.com; $9 per 3 cubic feet at Garden Fever, gardenfever.com). Gently tamp the area with your hands to fill in air pockets.
Water the tree thoroughly after planting. If it sinks after being watered, you must lever the roots up from below with a shovel and start over, replanting at the correct depth; then, firmly but gently, tamp the surrounding soil again with your hands.
Apply wood chips or bark mulch over the planting area, 2 to 4 inches deep and in a radius of at least 18 inches around the trunk—but be sure to leave a 2- to 3-inch circle of mulch-free space directly around the trunk. Your tree will grow faster if you keep the planting area clear of grass and weeds for at least three years, which will minimize root competition.