Pruning Overgrown Fruit Trees
by Jim Gormely
Several years ago I moved to a new property with a large variety of mature fruit trees. Some were 30 feet tall and had not been pruned for years. As a recently-certified Master Gardener, I discovered there are three basic methods for pruning an overgrown fruit tree back into a manageable size:
Method one: This method assumes that the tree is structurally sound and not much taller than can be easily managed with an available ladder. Use "thinning cuts" to remove any dead, diseased, broken or damaged limbs. Branches that cross or rub against each other should be pruned out, as should branches that grow toward the interior of the tree. The objective is to let sunlight penetrate to the lower fruiting branches. This can be accomplished by thinning the remaining canopy. Remove any branches growing beyond the height that you can reach to pick fruit. The tree will produce new vigorous shoots, especially near the top of the tree. The best time to remove these shoots is during summer pruning. Prune the tree to the same height annually.
Method two: If the tree is structurally sound but taller than you can manage safely, reduce the tree height slowly over a three-year period. Once you determine how tall you want your tree, cut one third of the excess each year. Major cuts should be made during April to reduce the chances of disease and infection at the pruning wounds. Rainfall may be less during this period and active growth hastens the healing process. Because large cuts stimulate new growth, remove or head back "waterspouts" once or twice during the summer to avoid shading lower fruit wood. Continue to thin additional branches as needed to allow some sunlight to penetrate into the canopy.
Method three: Drastically cut back all main branches but one. This is an extreme method of reducing tree height in a single season. Not all trees are capable of re-sprouting from such pruning. If you still want to try this extreme method, cut back main branches to a height that will result in a tree of the desired size. Branches may be cut to a length of 4 feet. Preserve and cut back lateral branches, even if the laterals are small. These laterals, along with shoots arising from buds on the main branches will form the framework for a new, smaller tree. However, a large root system remains and needs to be fed by photosynthesis. This photosynthesis process can be accomplished by leaving one smaller main branch or a large side branch (nurse branch). Remove or cut back the nurse branch the following year.
For a better understanding of this subject, mark your calendar for February 2, 2013 to attend a fruit tree pruning demonstration on open garden day at the Tuolumne County Master Gardener demonstration garden, located behind Cassina High School, 251 So. Barretta Street, Sonora. Hours are from 10:00 am - 1:00 pm.
This article is adapted from University of California ANR publication 8058 "Fruit trees: Pruning overgrown deciduous trees" https://ucanr.org/freepubs/freepubsub.cfm?cat=1 . Jim Gormely is a Tuolumne county Master Gardener.