Pruning for Plant Health
Fight Diseases and Increase Yields in the Organic Garden
Proper pruning methods can increase fruit and flower production, and discourage diseases by increasing air circulation and allowing light to reach the plant.
Pruning accomplishes more than improving the appearance of plants. When organic gardeners administer the right pruning methods at the right time of year, they can improve plant health without the use of a single chemical or pesticide.
The Right Tool for the Job
While gardeners can purchase a pair of garden clippers for under $10 at the local big box store, a quality pair of pruning shears is a delight to use. You can use a pair of anvil clippers for lightweight stems like rose canes, a set of heavy loppers for the small greenstick branches you find on hydrangeas or butterfly bushes, and a small handsaw for tree branches. Organic gardeners managing arthritis can buy ratcheting clippers, which require minimal hand strength for operation.
Fruit Trees
You must prune fruit trees in the late winter before bloom, but you can prune dead or damaged branches any time of the year. The goal of fruit tree pruning is to allow more light and air into the interior of the tree, to increase fruiting and reduce fungal diseases. Never top a tree by pruning the central leader, or you’ll permanently stunt its growth.
If you’re unsure how to prune your fruit tree, aim for a herringbone effect. In other words, remove branches growing from above or beneath the primary branch, and leave side branches alone. If you live in a climate affected by heavy snows or ice storms, consider removing any branches growing at a 90-degree angle from the trunk. These structurally weak branches are the first to break in bad weather.
Shrubs
The best time to prune spring-flowering shrubs is right after flowering. If you prune when the shrub is still dormant, in the late winter or early spring, you’ll reduce the beauty of the flower show. Spring flowering shrubs include lilacs, azaleas, forsythia, and viburnum.
Prune summer bloomers, such as butterfly bush and rose of Sharon, late in the winter season. These shrubs bloom on new wood and pruning encourages the formation of new flowering shoots.
Prune all broken branches and suckers. You can recognize suckers as vigorous-looking branches that sprout a few inches away from the parent plant. Suckers detract from the tidy appearance of the shrub, and weaken the parent plant by diverting nutrients. If you wish to train your shrubs into a hedge, keep the base of the hedge wider than the top. This decreases the chance of snow building up on the flat surface of the hedge and causing damage.
Roses
The best time to prune roses is in the early spring, when the buds on the canes have begun to swell. Remove any crossing canes, and any weak canes smaller than a pencil’s circumference. Make your cuts above an outward-facing bud, to encourage an open, vase-shaped growth pattern. In the past, rose experts advised painting each cut with glue or sealant to prevent cane borers from entering the plant. This isn’t necessary, as long as you make a clean cut with a well-sharpened pruning tool. Ragged cuts heal poorly if at all, and borers seek these crushed stems for their homes.
Source:
Rodale, J.I. (1999). Encyclopedia of Organic Gardening. Rodale Books, Inc: Emmaus, PA.
