Can You Trim Trees in Winter?

Gardeners must consider the season, weather and type of tree to time their trims.

While trimming trees can enhance their appearance and optimize health, the wrong timing can cause more harm than good. For instance, removing a diseased limb on a rainy winter day may encourage the disease to spread because wet tools are easily contaminated. The dormant winter period is usually a safe time to prune, but gardeners should consider the type of tree and the weather conditions before pulling out their shears.

Timing

Late winter, between February and early April, is the safest time to perform an extensive pruning job on a tree. Gardeners should wait until the worst of winter's cold has passed to avoid exposing the pruning wounds to ice and snow damage. During late winter, deciduous trees lack leaves that may obscure the limbs, making pruning decisions easier. After trimming, the tree will sprout new growths just in time for spring.

Exceptions

Some trees are early bloomers that require earlier pruning, according to horticulturalists Mike Zins, Deborah Brown and Mervin Eisel on the University of Minnesota Extension website. These trees include apricot, azalea, forsythia and magnolia. Gardeners should trim these trees, along with other early bloomers, immediately after the blooming period each year.

Evergreens

Though evergreen trees such as pines and firs also prefer late winter pruning, a light trim is safe at other times of the year, too. Most of these trees require little to no pruning, which makes most trims minor and purposeful. For instance, a broken branch may require immediate removal, regardless of the time of year. Gardeners can also safely liven up their evergreen trees with a light trim during the winter holiday season.

Bleeders

Some trees -- particularly maple, birch, elm and dogwood trees -- ooze sap when gardeners trim them in late winter. While this excretion does not harm the trees and will eventually stop, it is sometimes unattractive. To avoid this, gardeners may choose to wait until midsummer.

Warning

While gardeners should remove diseased or broken tree limbs as soon as possible, trimming in wet weather -- a staple of winter -- may lead to rot or tool contamination, according to the University of Idaho bulletin "How to Prune Coniferous Evergreen Trees." When trimming trees in winter, gardeners should wait for a dry day to safeguard trees' health.

References

• University of Minnesota Extension: Pruning Trees and Shrubs
• Virginia Cooperative Extension: A Guide to Successful Pruning, Pruning Evergreen Trees
• Iowa State University: The Proper Time to Prune
• North Carolina State University Cooperative Extension Service: Pruning Trees, Flushcuts and Wound Dressings
• University of Idaho: How to Prune Coniferous Evergreen Trees