Released: January 14, 2003

Winter Months Good Time To Prune Certain Trees

MANHATTAN, Kan. – Horticulturists who have made resolutions to avoid procrastination in the new year can get an early start in the winter months.

Landscape and fruit trees can be pruned the first three months of the year, said Ward Upham, Kansas State University Research and Extension Horticulture Response Center director.

"If you wish to do it early, the trees are fully dormant and have been for a few weeks," Upham said.

Pruning when temperatures are below 20 degrees F is not advisable, however, as there is a risk of injury to the wood tissue.

"It is important to do the pruning (on fruit trees) before dormant sprays are applied to the trees to avoid spraying some of the wood then pruning it out and discarding it," Upham said. "Also, you are more likely to get total coverage of limbs, branches and shoots after you have pruned."

In the sequence of pruning, prune older trees first, he said. The older, larger wood will tolerate low temperatures better than young trees with small diameter wood.

When pruning trees in late winter to early spring, some sap may flow from fresh pruning wounds. Different species of trees vary in how easily and how much they bleed, Upham said.

The most susceptible to bleeding include maples, specifically the silver, sugar, amur, Norway and hedge. Black walnut, pecan, birch, mulberry, Osage orange and grape are additional examples.

"Though bleeding may look as if it would cause considerable damage to the tree, this is not the case," Upham said. "Even if large amounts of sap are lost, there is no apparent long-term damage."

To those who find the appearance of this bleeding objectionable, winter pruning when temperatures are below freezing (32 degrees F) will help minimize sap flow.

"If you have any of the bleeders that need pruned," Upham said, "you might want to prune now rather than later."

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K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.

Story by:
Lucas Shivers, Communications Assistant
lshivers@oznet.ksu.edu
K-State Research& Extension News