"Pruning for strength": Pointers for properly pruning shrubs and trees
CLEMSON --When trees and large shrubs go toe-to-toe with Mother Nature, there's no guarantee that they will emerge unscathed from the onslaught of wind and ice. However, you can give them a fighting chance by creating and maintaining a strong, structural framework with proper pruning.
Try not to lose sight of the fact that pruning should be of benefit to the plant-not only to you. I know how empowering a tri-edged saw feels as it courses smoothly through a limb like a hot knife through butter. Or that feeling of pride and accomplishment that wells up inside when you stand back and look at your pruned tree like a sculptor admiring her handiwork. However, let's not lose our focus here. Pruning is not just about us. Pruning is supposed to improve the health and strength of trees. With young trees, the goal is to create a strong structure of trunk and limbs to support future growth. The objective for pruning large mature trees (usually by professionals) is to remove weak limbs to channel the tree's resources on the stronger remaining branches.
Prune trees now until early spring before new growth occurs. Spring-flowering trees such. as saucer magnolia, dogwood, and redbuds can be pruned after they bloom. They produce flower buds in mid-summer for next year's display.
Follow these "pruning for strength" steps:
1. Thin out dying, dead, or pest-ridden twigs and branches. Before you prune out a limb that looks dead, scrape the bark with your
thumbnail or a knife and look at the underlying tissue. A green layer indicates living tissue.
Cut back or thin out any damaged shoots by pruning within one-quarter of an inch above a live bud or just outside the branch collar.
Thinning is a term that describes the removal of a branch where it joins the limb or trunk. Use thinning cuts to remove crossing or rubbing branches, or to selectively remove inward growing branches to open up the center of the tree to sunlight. Thinning cuts are also used to "clean" or remove dead, diseased, broken, or defective branches from the interior.
A lot of growth can be removed by thinning without dramatically changing the tree's natural appearance or growth habit and giving it the "just pruned" look.
Heading cuts are usually reserved for shrubs and are generally undesirable on mature trees. Heading or heading back is a term that describes cutting a currently growing or one-year-old shoot back to a bud or side branch that's less then 1/3 the diameter of the cut stem. Heading results in a flush of new shoots just below the cut. Young trees can be headed back to encourage branching on long leggy branches.
Never head back the limbs of mature trees, including crapemyrtles. When mature trees are headed back, sometimes called topping or hat-racking, their structure is weakened or lost with the production of numerous snake-like sprouts, and the stubs that result are exposed to attack from insects and diseases.
2. Next, remove one of the branches that's rubbing or crossing over another. Wounds develop on rubbing branches which creates entryways for invading insects and diseases.
3. Remove branches that form a narrow, V-shaped angle with the trunk. Branches that form an angle less than 45 degrees from the trunk (10 and 2 o'clock) are weakly attached to the trunk.
4. Remove upright-growing side limbs that grow taller than the main trunk.
5. For general pruning, do not coat the wounds with pruning-wound paints. There is no scientific evidence that shows that dressing wounds prevents decay.
Besides experiencing the immediate gratification of properly pruning large shrubs and trees, think about the long term, living benefits to you and your landscape.
Funds for this project were provided by the Urban and Community Forestry grant assistance program administered through the SC Forestry Commission and funded by the USDA Forest Service and the SC Nursery & Landscape Association. For more information, go to http://www.scurbanforestry.org/ and www.scnla.com.