Minding Your Winter Garden: Trees Pruning - now is a great time to prune most trees and shrubs. However, do not prune azalea, dogwood, forsythia, redbud and rhododendron - they should be pruned after they bloom, since they set blooms in the fall. Almost anything that blooms after June 1 (except oakleaf hydrangea and late-flowering azalea cultivars) can be pruned safely now. Tree Planting - the winter months when trees are dormant are excellent times to plant. Be careful that you do not plant them too deep or with too much soil amendment.