Elisabeth C. Miller Library logo Miller Library Home UW Botanic Gardens Home UW Botanic Gardens Home book graphic

3501 NE 41st Street, Seattle, WA 98195 | (206) 543 0415 | Open Monday Noon-8; Tuesday - Friday 9-5; Saturday 9-3

Gardening Answers Knowledgebase


Knowledgebase record #15


Garden Tool A common question gardeners have is when to prune. "When the shears are sharp!" is the often-heard answer. In reality there are a few timing guidelines that do matter.

First of all, certain trees are known to "bleed" when pruned while the sap is rising in late winter and early spring. Maples, dogwoods, birch, elm, walnut and honey locust are the most common.
Bleeding usually won't hurt the tree, but the pruning cuts are slower to heal which may leave susceptible trees vulnerable to infection. These trees should be pruned right after leaves fall off in autumn.

Cherry trees are at risk from the destructive cherry bark tortrix. The tortrix is attracted to fresh pruning cuts, so cherry trees should not be pruned between May and August when the tortrix is active.

Spring flowering shrubs should be pruned immediately after flowering so that the new growth has time to form next year's flower buds. Summer flowering shrubs may be pruned in winter because flowers are formed on this season's growth.

Pruning resources online:

Keywords Prunus, Pruning, Juglans, Gleditsia, Cornus, Birch
Season All Season
Created Date 2007-05-17

Need an answer to your gardening question? Ask us directly!

Browse keywords or Search Again:

Keyword Search

We are continually adding new questions, so be sure to keep coming back.

June 24 2013 13:17:10