Pruning Trees and Shrubs
Established plants are pruned only for cultural or maintenance purposes. Improving structure is of primary importance. Work for uniform spacing of main stems and branches; thin out weak growth; eliminate weak crotches; raise the head of the tree gradually by removing lowest branches, starting at least two years after planting. Keep shrubs shapely and restricted by hitting-in young growth. Drastic pruning of shrubs should be done only by removing old wood to ground. Prune roses in spring.
Pruning Narrow-leaved Evergreens
Narrow-leaved evergreens may be thick and shapely and their growth suitably restricted by cutting back the ends of the branches. Pinching back a part of the tender, new growth is the simplest and usual method. Maintaining a neat evergreen hedge requires cutting back when ever the growth becomes irregular.
Pruning Broad-Leaved Evergreens
Tip prune the branches just before new growth starts to keep shrubs thick. Head back longer growth if necessary. Removal of faded flower clusters from Rhododendrons, Laurels and Andromedas to prevent seed formation is usually adequate pruning for them.
Regular pruning serves many purposes. Removing dead and diseased branches helps prevent the spread of disease and insect pests. Pruning improves the tree’s structure as well as its appearance. With a few exceptions, winter is an excellent time to prune your tree.
All pruning cuts should be made with clean, sharp tools and should be properly positioned and made in the proper order (see illustration to the right). Follow the steps shown for proper pruning cuts. Pruning paint is not needed.
How to Prune
-By the former Princeton Nurseries of New Jersey
During the transplanting process, trees of necessity lose a small portion of the root system they formerly had, whether they were dug bare root or with a ball of earth. To insure rapid, vigorous growth in their new location, the top should be pruned back so that there is a favorable balance of root over top. Damaged branches should be trimmed off below the point of injury. The central trunk or “leader” should be left intact to build a high crown and the side branches should be shortened. If trees are to be planted in containers or on landscape jobs, the branches should be thinned out and cut back by about one third of their length (see middle illustrations below). If the trees are to be planted in nursery rows for growing on, the branches should be shortened at least on half their length (see right hand illustrations below). This seems like harsh treatment, but the rapid regrowth which results more than justifies it. Broken roots should be cut off above the break and bruised ends cut off cleanly so they will regenerate more rapidly. Large B & B specimens benefit from having one-fourth to one-third of the branches cut out. This thinning improves survival rate and regrowth while still preserving the apparent size of the crown.