Deciduous fruit trees have dropped most of their leaves now that San Diego has had some cooler nights. It is important to remove the leaves and fruit from under trees since the leaf litter harbors the pests that are specific to that tree. By clearing under your fruit trees and composting the material away from the tree, you will avoid problems associated with those harmful organisms that overwinter in the fallen leaves and fruit.
In addition to clearing and weeding under your trees, now is a good time to add a layer of mulch. Mulching any growing area has many benefits: it decreases soil erosion and runoff, increases water holding capacity, suppresses weeds, and serves as a slow release fertilizer.
Mulches can be composed of organic or inorganic materials. The choice of what type of mulch to use is determined by availability of materials, what benefits are wanted, and aesthetics. Inorganic mulches include gravel, stones, sand, black plastic, or landscape fabric. Organic mulches include grass clippings, wood chips, straw, and pine needles.
Both organic and inorganic mulches will discourage weeds and run off, but the inorganic mulches do not break down and will not enrich the soil over the winter. If you want to feed your soil, put down a thin layer of compost around the trees and top with a thick layer (4″-6″) of organic mulch to discourage weeds. Mulch should not crowd up to the trunks of trees, so keep the material 6″to 12″ away from each tree. In your garden beds, keep the mulch an inch away from stems of flowers and vegetables.
Another task for fruit trees in the winter is pruning. The UC extension website is a useful resource for learning about fruit tree pruning. For more tips on how to prune your fruit trees, check out Solana Center’s Green Living Workshop: Fruit Tree Pruning Sunday January 4th, taught by Ari Tenebaum from Revolution Landscape.