Did you know that most species of fruit tree (including fruitless varietals) as well as American Elms should be pruned only during the winter dormant period? Apples, crabapples, pears, hawthornes, and mountain ash (sorbus genus) are susceptible to fireblight. Thus, these species should be pruned by early March. This gives the trees an opportunity to seal and heal their wounds before the bugs fly. When cut after spring bud, members of the rose family can become infected by this bacteria which are usually transmitted by insects.

Another benefit of winter pruning is reduced probability breakage of branches in heavy spring snow.

Cleaning and sanitizing tools with dentured alcohol or soapy bleach solution prior to pruning each individual tree or plant prevents infection from spreading from one tree to the next via pruning tools.

Winter/dormancy is also the best time of year to prune shrubs as cutting large a percentage of the plant is possible, which would distress or kill it during the growing season.