"Pruning for strength":
Pointers for properly pruning shrubs and trees
By
Bob Polomski
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.