Tree Facts: Pruning trees and shrubs

Most plants can be pruned at almost any time of year without jeopardizing basic survival. However, it is preferable to prune specific plants at specific points in the year. Trees and shrubs that flower before the end of June should be pruned immediately after flowering. Other trees and shrubs, those which flower after the end of June, should be pruned in winter or early spring before new growth starts.

Proper pruning requires good tools, using them correctly and maintaining them. Some of the more commonly used tools are HAND SHEARS – for branches up to 1/4” diameter, POLE PRUNERS – for branches beyond arm’s reach, LOPPING SHEARS – For branches up to 1-1/2” diameter, HEDGE SHEAR – for clipping new growth into formal shapes and PRUNING SAWS – for branches over 1” diameter.

The three basic pruning techniques are pinching, thinning and heading back. Pinching involves using your hands to break off growing tips to control plant size. Thinning involves using tools to removes some branches back to a main branch, trunk, or soil line. Heading back involves trimming branches back to a good bud or lateral branch.

When pruning broadleaf shrubs, cut above a bud to prevent dieback of the stem and encourage a new branch to develop from the bud. Remove branches which tend to rub against each other and dead, damaged, or diseased branches. Also, remove dead flower branches, dead flowers, and old fruit stocks as soon as the flowers have wilted or the fruit has dropped. Declining shrubs can be rejuvenated by cutting them back to ground line. Many new shoots will grow from the base that may require some thinning.

Large trees need pruning to prevent injury and damage to life and property. This usually involves the removal of large branches or limbs from trees. Low-hanging branches may cause injury to individuals mowing the lawn or walking on the street. Also, branches sometimes rub against the house and roof. To remove the branches that are over 1″ in diameter, use the double cut method. First cut halfway on the underside of the limb, second make a cut clear through several inches further out on the upper part of the limb. When the branch is removed, there is no splintering of the main tree trunk. Then remove the stub by conventional methods, taking care not to cut into the branch.

With evergreen shrubs, avoid shearing, prune using the thinning technique, do not cut branches back to the old wood. Reduce new growth annually, and when removing the larger branches for thinning, cut close to the main trunk, leaving no stubs. Heavy thinning is needed only every few years. Pinch out 1/2 of the candle (the new growth) when it is approximately 2″ long in the spring, to thicken the new growth of coniferous trees such as pines, spruce, or fir. If the terminal of a pine or spruce has been lost, form a new one by bending one of the youngest lateral branches near the terminal into an upright position.

Basic pruning includes adherence to basic safety rules. 1. Call in a professional for large jobs you don’t have the equipment for. 2. Keep all equipment sharp and in good repair. 3. Use equipment only for the job it was designed to do. 4. Be conscious of electric lines when pruning near them. 5. If a power line is touching a tree limb, call the power company fast and stay clear of the tree. 6. Never climb a tree without a safety rope, with or without a ladder. 7. Keep your fingers clear when using hand clippers. 8. Use care in handling pruned limbs and brush to avoid eye injury.

My source for this news release was Purdue University Cooperative Extension Service. If you would like more information about “Pruning Trees and Shrubs,” contact Bob Drown at the Conservation Office at 605-244-5222, Extension 4 or by e-mail at robert.drown@sd.nacdnet.net.