Judicious pruning shapes and guides your shade trees over the years

Beautiful shade trees, conspicuously dotting a landscape and surrounding a home, usually do not happen accidentally.A lanscape having choice trees, strategically planted, is the result of pruning as part of a regular maintenance program.

While a little trimming here and there is bound to improve your trees, continual improper pruning can result in severe damage or decline to your deciduous plants. Pruning should not be done at the gardener's convenience, but only when the trees will benefit in maximum plant growth.

Even though you can prune trees almost at any time of the season, the best time of year is late winter or early spring just prior to the start of plant growth. This time of year is probably more desirable because the tree wounds heal more quickly when growth begins in the spring. Maples, birches, flowering dogwoods, and walnuts are exceptions because they bleed severely when pruned at this time. Wait to prune them in midsummer when the sap will not flow so freely. Also, wait to prune flowering trees till after they have bloomed.

There is an exception, however. Even in midwinter, if branches snap and crack in heavy ice storms, you would be wise to remove these laterals to protect the tree and perhaps any nearby property.

To remove these potential storm-damage branches, first cut the underside of the branch as close as possible to the trunk to lessen the chance of stripping bark from the tree when you cut all the way through from the top. Remove any large heavy branches in two or three stages, starting at the tip and working back to the trunk. You may need to tie around the cut-off branches to keep them from damaging the rest of the tree when they fall.

If the branch is not a main lateral, angle the cut so the stub will allow water to run off. Also, trim the ragged edges with a sharp knife to speed healing. Then use an asphalt-based tree-wound seal to keep water and disease out. Swab large wounds with denatured alcohol to kill any germs before using the tree-wound paint.

Usually, if you plan the growth of your young trees around your property, you may not have winter tree limb cutting problems. Early pruning to direct young tree growth is very important if you want your mature tree to function as expected in the landscape.

You must keep in mind that the growth habit of a tree and your landscape use should determine how and to what extent you need to prune to train growth to a desired form. Early corrective measures of undesirable branches or shoots while the tree is young eliminate drastic pruning later on.

The training should begin at planting. Young trees should be pruned to develop a good basic start. Remove broken or damaged branches and roots and any branches not suitable to form the main framework or to shape the tree to a somewhat symmetrical form.

Make sure you don't prune the central leader unless you desire multiple stems , as in certain small flowering trees.

Trees with a central leader and conical shape may need hardly any pruning at all; for example, conifers, sweet gum, and pin oaks. Trees with irregular growth habits, vigorous lateral branching, and poor branch structures, such as the silver maple, may need quite a bit of pruning.

Prune your young trees, then, only enough to direct the growth effectively and to correct any structural weaknesses. The branches you select for the permanent scaffolds, or main limbs, should have wide angles of attachment to the trunk (see Figure 1) for greater strength.

As already noted, depending on the tree use, such as screening, windbreak, a patio protection, or fencing along a driveway, you should determine the height of the first permanent branch above the ground because the position of the limb on the trunk remains the same throughout the life of the tree.

But your young tree may not be tall enough at planting for you to determine any permanent lateral branches. Simply allow them to grow as temporary laterals. After two or three years, when the trunk is two or more inches in diameter, you can reduce these temporary branches gradually. Remove the largest ones at each pruning to lessen pruning wounds.

Horticulturalists suggest pruning to direct tree growth during the growing season as well as the dormant stage. During the growing season confine your pruning to temporary shoots and branches. Removing a shoot will reduce competition with the leader or branches selected as permanent scafford limbs.

Sometimes you'll need to pinch off the tips of temporary branches from these young trees to keep them in bounds and to reduce competition.

Another way to direct growth is to stimulate new growth from already formed buds. You can encourage your tree to spread desired laterals by selectively cutting off branches opposite forming buds (see Figure 2). To facilitate healing make slanting cuts just slightly above the bud.

Also, inspect your tree carefully and note young buds appearing on the main trunk. If you think a lateral branch will spoil the shape of the tree or give the leader or other lateral branches competition, merely rub off the bud.

Paint on a little tree-wound dressing to reduce damage and prevent disease. Also, prune the ends of permanent branches that are too long or crooked or cross over other branches.

Pruning as a regular, methodical maintenance procedure means repairing damage , controlling size, improving form, or inducing and directing more branches from buds. All these techniques can help you maintain and direct the growth of your shade trees in a well-planned landscape.