This week’s garden tip was submitted by Wally Schmidtke, sales manager at Pesche’s Flower Shop and Garden Center.
Last fall we aggressively pruned our lilac bushes; this spring they didn't flower! What happened? This question is frequently asked.
If you prune your lilacs in the fall or late winter and they will not flower the following spring, or possibly for a couple springs. Lilacs set their flower buds on old wood in the fall, which will bloom the following spring.
There is a time frame of about two weeks after the lilac flowers and the flowers dry to accomplish this chore. Lilacs pruned in this manner will flower robustly the following spring. Broken branches or limbs that rub against each other can also be pruned at this time.
Other spring flowering plants that bloom on old wood, and, therefore, should be pruned on the same schedule as lilacs include dogwood, bridal wreath, spring-blossoming spirea, forsythia, honeysuckle bushes, viburnum, weiglea and deutzia.
Remember to clean your pruners with rubbing alcohol before and after pruning. Avoid using high nitrogen lawn fertilizers around your spring-flowering trees and shrubs because it can cause excessive leaf growth and poor flowering.