Judging from e-mail messages and personal comments, my recent column on pruning rhododendrons was helpful to many readers. I am encouraged to return to pruning for another column or two, beginning with a focus on a large and diverse group of garden plants: deciduous shrubs.

Deciduous shrubs can be divided into several groups, each represented by one or more popular species. This article deals with the shrubs that bloom in early spring from buds produced during the previous growing season. Examples include forsythias (Forsythia x intermedia), beautybush (Kolkwitzia amabilis), mock orange (Philadelphus sp.), and all spring-flowering spireas (Spiraea sp.).

Forsythias are some of the most abused plants on earth, suffering humiliation when we ignore their natural habit of growth and try to force them into grotesque geometries: squared hedges, boxes, meatballs, Egyptian pyramids. The result is a tangle of old crowded stems that flower only sparsely and drop their lower leaves, either from lack of light or embarrassment. Forsythias, as well as the other members of this group, should be pruned to accentuate a natural form of branches that grow upward and outward, stiffly arching down to earth under the weight of spring flowers. This pruning should be done with hand-pruners, loppers and a small pruning saw.

Proper pruning begins with understanding both the season of bloom and the flowering habit of the shrub. In early-spring-flowering shrubs, the flower buds form either on short lateral branches produced on the previous year’s growth, as in mock orange, or directly on the 1-year-old branches, as in forsythia. One or more strong shoots will have developed below the flowering branches. This group also shares the common trait of producing much of the new growth from ground level.

Prune plants in this group in early spring, immediately after flowering, cutting back the stems that have flowered to the lowest (and usually the most vigorous) of the developing young side branches. These young stems will soon form next spring’s flower buds. In addition, completely remove one-third of the old stems at their base, taking care to balance the shape of the plant. These old stems will be replaced by new stems from ground level, which will grow vigorously the first year and form flower buds in their second growing season.

Combining this approach with the Three Ds (see sidebar) will enhance the health and beauty of your forsythias and other early-spring-flowering shrubs for years to come.

Send queries to Gardening Questions, P.O. Box 418, Ellsworth 04605, or to reesermanley@shead.org. Include name, address and telephone number.

Pruning tips

Pruning should be done as often as necessary, regardless of season. There are two important aspects to this care:

. Inspect your shrubs often and carefully, looking for the Three Ds: dead, damaged or diseased wood. Remove a problem branch just above the point where it joins a healthy branch or at the base of the shrub.

. While pruning to enhance flowering, selectively remove branches to keep the shrub open in the center. This will improve air circulation and enhance quick drying of the foliage, important factors in minimizing foliar diseases, including mildews, rusts and black spot. An old adage is to keep the branching sufficiently open to throw a cat through the shrub. Being fond of cats, I only use this maxim metaphorically, but the concept is worth remembering.