An important maintenance activity each gardener must perform is pruning of woody ornamental plants and trees. Pruning systematically removes plant parts to increase the value of a plant, by maintaining its health and vigor, modifying its form and size, modifying its flowering or fruiting, and maintaining an attractive plant. It also removes injured, dying, or dead wood, eliminating entry points for insects and disease, encourages branching and bushy growth, and rejuvenates the plants. At Cornell Cooperative Extension of Oneida County’s Parker F. Scripture Gardens, (121 Second St., off County Route 840 Town of Whitestown) we will be pruning the deciduous shrubs throughout the garden during the year.
There are three reasons for pruning deciduous shrubs:
(1) to "thin out", opening up the plant to light and air, establishing its structure, and directing its growth;
(2) to "head off" the plant, shortening plant stems, making the plant more dense, and reducing its height without changing its natural shape; and
(3) to renew the plant and/or rejuvenate old or overgrown ones, removing the oldest and largest, broken, damaged, dead or diseased and unattractive or unruly branches. Pruners must assess the whole plant before making any pruning cuts, and never make a cut without knowing the reason for doing so.
The time of year for pruning depends upon the type of plant, the desired outcome, and the severity of pruning. However, remedial pruning to remove broken, dead, or diseased branches can be done at any time with little negative effect on the plant. Whenever material is removed from a plant, through natural causes or by pruning, the plant will usually respond by making new growth elsewhere. In general, the harder the pruning, the more vigorous the re-growth will be.
General pruning principles are:
Spring and early summer-flowering shrubs flower on the previous season’s growth. When pruning plants that are grown for their spring flowers, prune last year’s growth soon after they bloom to permit new wood to grow and ripen to bloom the following year.
Late summer and autumn flowering shrubs that flower on the current season’s growth do so from buds formed that same spring, and so prune in late winter/early spring to encourage vigorous shoots that will flower the same year.
Prune evergreen and deciduous shrubs grown for foliage in late winter/early spring before new growth starts.
For more information contact the Extension Office Horticulture Hot Line Wednesdays and Fridays between 9 a.m. and noon at 736-3394 x 127 or check out the website at http://counties.cce.cornell.edu/oneida/.