Winter is a key period for maintaining deciduous fruit trees, particularly in home orchards where stone fruits such as apricot, cherry, peach, nectarine, plums, and prunes, as well as pome fruits like apple and pear, are common. Maintenance activities during this season focus on sanitation, pruning, and the application of dormant or delayed dormant sprays to reduce insect and disease problems during the growing season.
Sanitation involves removing and destroying old fruit from both the tree and the ground to eliminate sources of insects and diseases for the following year. Raking up fallen leaves under fruit trees is also recommended to further decrease pest populations.
Pruning is another important winter task that supports pest management by promoting tree vigor and improving sunlight exposure and air circulation within the canopy. All fruit trees benefit from pruning out dead or diseased branches, crossed or broken limbs, water sprouts (upright shoots), and root suckers. The extent of annual pruning varies by species: cherries require about 10% removal; peaches and nectarines need about 50%; plums and prunes about 20%; apples and pears between 15–20%. Apricot trees are an exception in the Bay Area due to their susceptibility to Eutypa fungus spread by rain; these should be pruned six weeks before or after the rainy season.
Summer pruning is also possible for fruit trees. This method helps control tree size, making maintenance tasks like harvesting easier. For more detailed guidance on pruning techniques—including diagrams—resources are available at the University of California Integrated Pest Management website (https://ipm.ucanr.edu/PMG/GARDEN/fruit.html). Additional information on summer pruning can be found at https://ucanr.edu/site/uc-marin-master-gardeners/article/summer-pruning-fruit-trees. Advice on cutting back overgrown trees is provided at https://ucanr.edu/blog/stanislaus-sprout/article/cut-those-overgrown-fruit-trees-down-size.
Dormant or delayed dormant sprays may help manage certain diseases and overwintering pests. These treatments involve applying pesticides such as fungicides or oils when trees are dormant or just beginning bud swell. It is essential to identify which pests or diseases are present before choosing a pesticide and to follow label instructions carefully. Decisions regarding spraying depend on previous seasons’ pest issues; spraying after pruning can improve coverage if treatment is needed. More information on winter pest management in backyard deciduous fruit trees can be found at https://anrcatalog.ucanr.edu/pdf/8368.pdf.
The UC Master Gardeners of Contra Costa County offer additional support through their Help Desk service.
