How to Select and Plant Trees

by Elmer Krehbiel, Master Gardener
October 31, 2003

Trees should be selected for their form, shape, texture and color. The most valuable trees for the Brazos Valley are bald cypress, cedar elm, magnolia, bur oak, live oak, Texas red oak, pecan and Chinese pistache. The large crape myrtle and yaupon shrubs may be pruned to a small tree form.

Some trees are considered ornamental because they have attractive colorful flowers or fruit, interesting foliage, colorful leaves, interesting bark, winter foliage or interesting shapes.

Trees are used for dense or light shade, windbreak, screen, or special ornamental purposes. Those trees selected for screening or windbreaks are usually evergreens that develop dense foliage.

Consider the location and mature size of trees before selecting and planting them. Many species will become too large for a small space and under utility wires.

The maintenance required should be considered and disadvantages, such as, soft or brittle wood, some roots grow along the surface of the ground, fruit or seeds are trashy and smelly, twigs are trashy, etc.

It is probably impossible to transplant trees without damaging the roots. The smallest trees should have the least root damage, and be selected for heavy soil. Even the container-grown plants should be transplanted before the roots grow against the sides.

Limbs should be flexible, with plump buds. I prefer a tree that has not been pruned, and it is only two to four feet tall, with a healthy terminal bud. Then I expect it to develop the natural shape and size of the species. In a few years, they will equal the size of those that were larger when transplanted and are expected to continue at a faster growth rate.

Plant Trees in the Fall

The major reason to plant trees during the early fall is so they will grow more roots while the soil is cool. Many plants stop growing when the soil becomes too warm. The critical temperature varies according to the species.

The garden stores and nurseries may have more trees of various species and sizes during the fall, as growers prepare and ship fresh plants.

A digging law became effective on October 1, 1998. Before digging to plant a tree, set a post, etc., call the above one number for permits from all underground utility lines. CALL 1-800-545-6005.

The planting hole should only be as deep as the roots, but at least twice wider. If the tree requires good drainage, do not dig that much and drag topsoil up to it. More trees are probably lost because they are planted too deep than for any other reason.

About 90 percent of the roots will grow out within the top foot of soil. If you loosen the soil a foot deep with a spade or soil fork farther out, it will be easier for the trees to grow faster.

If the roots are tightly coiled, they should be horizontally spread out at planting time. The girdling can prevent normal growth and usually causes the trees to become root bound and die several years later.

The trees should be set in the center of the hole and you should apply half of the topsoil excavated for backfilling around the roots. The soil should be soaked with water and the trees wiggled so air will bubble up from under the roots. Then finish applying the backfill and apply more water.

Caring for New Trees

Do not apply granular fertilizer, but use water-soluble fertilizer at planting time and during the first year.

A berm should be graded up around the trees for a basin over the root system to apply additional water as needed. The basin around small trees should be large enough for about five gallons of water, and increased for larger trees.

Apply a three-inch deep mulch at least three feet around the trees after planting to retain moisture, stabilize the temperature, prevent mower and trimmer damage, etc.

Then prevent all competition from other plants around it. Grass and flower roots are also in the top foot of soil. They are faster growing plants, so they will absorb the soil moisture and nutrients before the trees. If you must have both, then be sure to provide extra water and fertilizer for both of them on a regular time schedule.

If trees need some support, the material should be soft and attached loosely so the wind can move it some. The bark should not be damaged by the attachment. Movements from the wind help develop a stronger root system.

Do not apply any granular fertilizer the first year, one-half pound of nitrogen per inch of trunk diameter the second winter and up to one pound each winter.

Additional water may be needed each week in the basin, with a soaker hose or a root-watering attachment for the garden hose.

If the lower branches are allowed to grow, the roots and trunk will develop more size. If you plan to be under the tree when it is mature, gradually prune the branches when they are about an inch in diameter. They should be pruned up to about seven or eight feet high.

More on Planting Trees

Dr. Elmer Krehbiel is the former President of Keep Brazos Beautiful. See his column in The Eagle.