By Richard Jauron—Iowa State University Extension and Outreach
Fruit trees should be pruned to obtain good yields of high-quality fruit. There are three important aspects to pruning fruit trees, timing, frequency, and procedure. Horticulture specialists with Iowa State University Extension and Outreach share information on how to prune fruit trees. To have additional questions answered, contact the Hortline at (515)-294-3108 or hortline @iastate.edu.
When Should I Prune Fruit Trees?
Late February to early April is the best time to prune fruit trees in Iowa. Summer pruning of fruit trees is generally not recommended. However, water sprouts (rapidly growing shoots that often develop just below a pruning cut) can be removed in June or July.
They should also be pruned on a regular basis, and annual pruning of young (non-bearing) fruit trees develops a strong framework and a desirable shape. Annual pruning of bearing trees maintains tree vigor, maximizes fruit yields, and improves fruit quality. Young trees require light annual pruning. Bearing trees require light to moderate annual pruning. Insufficient pruning of bearing trees may result in small, poorly colored fruit with a low sugar content and mediocre flavor. Excessive pruning of bearing trees weakens trees and results in vigorous shoot growth with little or no flower bud formation, resulting in a poor crop the following year.
How Do I Renovate a Neglected Tree?
A large, neglected apple tree that hasn’t been pruned for several years is often densely branched, unproductive, and may contain a number of dead branches. Fruit produced on neglected trees is generally small, misshapen, poorly colored, and has a low sugar content. If properly pruned, large, neglected apple trees can produce good quality fruit. Pruning increases fruit size, promotes better color development, increases sugar content, and decreases insect and disease problems by allowing better spray coverage and faster drying following rainfall. Pruning also makes it easier to harvest the fruit. Complete renovation of neglected apple trees may take two or three years.
The first step in the renovation of a neglected apple tree is to prune out all dead, diseased, and broken branches. Next, remove undesirable interior branches. Prune out the weakest of crossing limbs and closely growing parallel branches. Also, remove limbs growing toward the center of the tree, strongly growing upright branches, and water sprouts. (Water sprouts are rapidly growing, vegetative shoots that develop on larger branches or the tree trunk. They often form just below a pruning cut.) Prune off low-hanging branches. Finally, remove weak, spindly growth if additional thinning is necessary.
For more information on pruning fruit trees, refer to the ISU Extension and Outreach publication Pruning and Training Fruit Trees.