This column is written by the Master Gardeners of Yolo County each month. It provides answers to selected questions recently asked by Yolo County gardeners.
Question: Should I prune my fruit trees? If so, how?
Answer: Yes, most fruit trees benefit from regular pruning. Done correctly, pruning improves tree health, fruit quality, and long-term productivity. How and when you prune depends on the type of fruit tree and its age. Since we have hot summers and mild winters, timing matters.
Pruning serves several purposes. It improves the structure so branches can support fruit without breaking. It increases air flow, reducing some diseases and exposes inner branches to more sunlight, increasing productivity and fruit quality in some species such as peaches and nectarines. It controls size, making harvesting and maintenance easier.
Most of the suggestions here apply to deciduous fruit trees. Citrus should be pruned only in late spring after the risk of frost has passed. Citrus trees require less pruning than deciduous fruit trees. Prune citrus to remove dead or crossing branches and to remove those that are trailing on the ground.
There are two main pruning seasons: late winter, for dormant pruning of deciduous fruit trees, and summer, for a light but important reduction in tree size. Dormant pruning for most deciduous fruit trees is best done in January and February. Apricots and cherries are pruned only in the summer because of susceptibility to a fungal disease, Eutypa dieback (Eutypa lata). Open pruning wounds during wet weather provide an opening for fungal spores.
Winter pruning will stimulate vigorous new growth and is the best time to take off large branches, if necessary. Summer pruning is usually done in mid-summer, generally after harvest for summer-bearing trees. It allows you to better control the tree’s height, for your safety. It is the time to remove vigorous first-year growth that grows straight up (water sprouts) and improve light penetration. Leave enough leaf cover to produce a dappled shade in the center of the tree. To prevent sunburn, large horizontal branches and the trunk are best protected with white water-based paint diluted 50/50 with water or tree whitewash.
Whenever you are pruning, use clean, sharp tools. Start by removing dead, damaged, or diseased branches. Cut out branches that cross each other. Remove suckers from the base of the tree. Thin crowded areas so light can reach the interior.
Most stone fruits (peaches, nectarines, and apricots) are pruned to have an open center. With a young tree, choose three to five main scaffolding branches that are evenly spaced and growing out more than up. Prune out other large branches, especially those growing vertically in the middle. Maintain this “vase” shape throughout the tree’s life. For an older tree that has not been properly pruned, reach this shape in a three-year process. Pome fruits (apples and pears) are generally pruned to one or two vertical central branches (leaders). Allow evenly spaced branches to extend out from these.
There are two main types of pruning cuts: thinning and heading. A thinning cut removes an entire branch. Cut just outside the branch collar (the slight swelling where the branch meets the trunk or a larger branch). A heading cut removes an end portion of the branch. Heading cuts are often made just above a lateral branch, which will then direct the growth out rather than up. As a general rule, you can remove twenty to thirty percent of a tree each year to limit its size and promote vigorous fruiting on the remaining branches.
Focus on annual dormant pruning for structure and health, use summer pruning sparingly, and tailor your approach to the tree type. Done consistently and properly, pruning will reward you with healthier, reasonably sized trees and better fruit for many years. Here are three resources for additional information:
UC Master Gardeners of Santa Clara County's The Backyard Orchard - Pruning (1/1/2025 pdf) and The Backyard Orchard - Pruning (2/12/2021 video)
UC Master Gardeners of Marin County's Pruning Tips - Fruit Trees
UC Master Gardeners of Sacramento County's Summer Pruning
Have a gardening question? Send it to jmbaumbach@ucanr.edu, with “Ask MGs” in the subject line. Include as much detail as possible and pictures if you have them.