Cane Shrubs (Forsythia, Buddleja alternifolia, Deutzia, Philadelphus)
Cane-growing shrubs are usually fountain-shaped. These shrubs can be quite graceful if left to grow naturally, and shortening the canes will destroy the shape of the shrub. Take it from someone who once thought she knew better than mother nature how a forsythia should be shaped — it takes quite a while for the shrub to restore it’s flowing shape.
Early cane-flowering shrubs produce flowers on shoots that grew during the previous year. Pruning them right after they bloom will give them the longest possible time to produce long, vigorous shoots for flowering. Remove old, weak branches at ground level, and prune out any dying shoots or branches that are taking off in awkward directions.
Evergreen Shrubs (azaleas, camellias)
Evergreens that flower in spring usually flower after the caning shrubs. These include azaleas, rhododendrons and camellias. Use a light touch when pruning these shrubs. Prune just enough to maintain the shape of the plant. As with the caning shrubs, they should be pruned right after they flower. Pruning later in the year will interrupt the developing buds.
If your evergreen shrub is hopelessly misshapen or has been neglected, you can cut it back to 12 to 18 inches from ground level. It will regrow, and you’ll have a much more shapely shrub.
Deciduous Shrubs (Lilacs, some Magnolias)
Lilacs and similar evergreen shrubs flower on growth from both the current year and previous years, and need very little pruning. In late winter or spring you can remove wayward or crossing branches and any damaged limbs.
