Prune most deciduous trees and needle-leaf evergreens in the late winter or early spring when they are dormant and before new growth begins. Certain deciduous trees such as beech, birch, dogwood, elm, maple and sycamore will bleed excessively if pruned at this time, so wait until summer to prune them.

Early-spring flowering shrubs like Azalea, Forsythia, Rhododendron and Spirea can be pruned just after flowering.

Prune evergreen hedges such as Buxus, Yew and Tsuga in the early spring, just before new growth begins.

Finally, prune all roses in early spring except climbers and ramblers; they need pruning only after they flower.

Read more in our guides Proper Pruning of Shrubs, Introduction to Pruning, Conifer Planting and Pruning, Proper Pruning of Trees  and Pruning Roses.

Courtesy of the NYBG Plant Information Service