Give your pruning sheers a workout

Winter is a good time to prune trees and shrubs. Heavy pruning of overgrown, deciduous, woody shrubs can be done this month and next to rejuvenate them.

Start by removing all dead wood and prune old canes off at ground level, leaving young canes. You may need to cut back the young growth if it is spindly.

If there are not any young canes present, cut the large canes back to 2 to 3 feet from the ground. This will be unsightly, but if the plants are healthy, extensive new growth should start from the old canes in spring and fill in the plant.

Shrubs such as lilacs that formed flower buds last summer will not bloom in spring when pruned aggressively in the previous winter.

Branches with interesting foliage, as well as flowering branches, can be forced. Prune those branches that are not essential to the plant's basic shape, or save branches from your winter pruning. Branches should be at least 1-foot long, full of fat flower buds and cut on a day above freezing. Cut the ends at an angle and put into water in a cool room out of direct sunlight. When the buds color up or the foliage begins to unfurl, arrange the branches in a vase and display them in a cool room out of direct sunlight.

Good choices for forcing this month include the following: serviceberry (Amelanchier), magnolia, flowering quince (Chaenomeles), forsythia, crabapple or apple (Malus), flowering pear (Pyrus), flowering cherry (Prunus), spring-flowering witch hazel (Hamamelis vernalis) and redbud (Cercis).

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.