Wouldn’t it be wonderful if every plant we purchase matured into the perfect size and shape for our landscape? Unfortunately, this is often not true. Most trees and shrubs require periodic maintenance to be at their best. This maintenance includes pruning – a multifaceted topic! There is no absolute set of rules to govern the pruning of all trees and shrubs. Each plant must be considered individually.
Most trees should be pruned while dormant. This is the period in which buds are not growing or seeds are not being produced. Dormancy is easily recognized in deciduous trees as they lose leaves and we rake! This is not so easily recognized in evergreens because they remain green all year. However, evergreens do not grow or produce seeds during dormancy. This period normally occurs during winter in our area.
Pruning tends to stimulate new growth. That growth may be damaged by freezing weather in late fall to early winter. In general, it is preferable to wait until broadleaf plants are completely dormant to prune. Usually in our zone, 8a, this occurs from late December until buds begin to swell in the spring.
There are some general rules to follow when choosing a time to prune. Spring- or winter-blooming shrubs and trees should be trimmed after their bloom cycle is complete. If pruned in the winter, flower buds will be destroyed and spring bloom will be lost. This group of trees and shrubs includes dogwoods, parsley haws and redbuds. Summer- or fall-blooming shrubs usually bloom on new wood formed in the spring. The proper time to prune summer-to-fall-blooming plants is during dormancy. Plants falling into this category include sasanquas, roses and beautyberry.
Conifers or needle-leaf plants, such as junipers, cypress, arborvitae or hemlock, are not tolerant of heavy pruning. If new growth is lightly sheared in the spring, these plants will become denser. For conifers, pruning should be limited to the removal of dead or injured branches. If possible, allow conifers to develop their natural shape.
Removal of dead, diseased or crossed branches may be done at any time for general maintenance. Also, suckers, insect-infested plant parts and branches or limbs that present a safety hazard can be cut away at any time.
If you are planning to prune a plant, consider your goal. Maintaining the natural shape of a tree or shrub requires thinning. To accomplish thinning, the branch is cut back to the limb or trunk from which it originates. Thinning cuts are made to dead, diseased, crossed or crowded branches.
Controlling the size of a plant requires heading cuts. These cuts should be made using a hand pruner. The cut should be made above a bud. Bear in mind that heading cuts can direct the growth of a branch. Often it is preferable that the bud points away from the center of the tree.
Fruit trees need special consideration. Most of them require annual pruning, especially nonbearing young trees. The goal of fruit tree pruning is to get light into the tree canopy. They are to be pruned in late winter and again in summer, if needed.
LSU has excellent bulletins available on pruning. Consult those or your local LSU AgCenter agent if you have concerns.
Finally, consult a professional to prune limbs growing near or on overhead wires, that may damage property as they fall, or that you cannot prune without a ladder. Always consider safety when planning pruning projects.
This article was written by Donna White, Lincoln Parish Master Gardener.