Prune trees and shrubs in winter
FOR IMMEDIATE RELEASE
November 5, 2012
Do you have a tree or shrub that needs pruned? Possibly it has dieback from this summer's drought or Japanese beetle feeding, or maybe it has outgrown its space. Rhonda Ferree, University of Illinois Extension educator, horticulture, says that winter is a great time to prune woody plants. "There are many advantages to pruning plants during the winter months between leaf-fall and spring growth."
"Pruning during the dormant season tends to result in more vigorous growth the following season." "Much food is stored in the roots and main stems, and the removal of a part of the top reduces the number of buds or growing points." When growth starts in the spring, the stored foods are distributed to the fewer growing points in increased amounts, resulting in more vigorous growth.
Nearly all books on pruning recommend that spring flowering shrubs such as lilac and forsythia be pruned after they have bloomed. Ferree says that while it is true that pruning these plants after flowering will permit a maximum number of flower buds to develop for the following year, the practice may not always be the best. "This is partly because summer pruning typically consists of merely removing old flowers, trimming and cutting back rather than pruning."
"Another big advantage of pruning a deciduous plant in the winter is it allows you to see the framework to determine which shoots or branches should be removed. I like to remove dead and dying parts first," says Ferree. "You can tell if a stem or branch is alive by slightly scratching it with a key or fingernail. If green shows through underneath the bark, it is alive." Once the dead material is removed, you can see if the plant needs thinned further.
Multi-stemmed shrubs are often renewed in the winter by removing a number of old stems to promote new growth, maintain moderate size, and encourage flowering and fruiting. Every two or three years cut out the largest stems at the crown to stimulate new growth from the crown and remaining stems. Be careful though when initiating renewal pruning on large or old plants as immediate results may be unattractive.
For evergreens, winter pruning is sometimes preferable when an evergreen has become straggly as a result of long neglect. The long branches are cut to encourage new bud development early in the next growing season. When summer pruning is done, new buds will not develop until the following spring and the plant will remain unattractive all season. If possible try not to cut beyond green growth on evergreens. Evergreens can be difficult as not all evergreens can be pruned in the same manner at the same time.
"And finally, says Ferree, please never top a tree." Tree topping has no real benefits and actually promotes decay or death of remaining branch stubs. Topping also produces weak branches that are more susceptible to pest and storm damage. But most importantly, topping destroys a tree's natural shape and beauty.
University of Illinois Extension has videos available online at http://urbanext.illinois.edu/video/ that show you how to prune various types of plants.
Source: Rhonda J. Ferree, Extension Educator, Horticulture & State Master Naturalist Coordinator, firstname.lastname@example.org