Fallen leaves can be a useful resource for gardeners, according to the Yolo County Master Gardeners. Instead of leaving leaves on the street for county pickup, residents are encouraged to use them in their own yards and gardens.
When leaves are left for collection, the county shreds and composts them before selling the finished product to local farmers. Some of this compost is also made available free to county residents. However, using leaves at home as mulch or compost can provide direct benefits.
Leaves used as mulch help prevent weed growth and reduce water evaporation from soil. Organic mulches like leaves also increase soil nutrients over time. For effective weed suppression, a mulch layer should be at least three inches thick and kept away from plant stems or tree trunks to avoid disease or rot. It is important to check that the leaf layer does not become matted so water can reach the soil.
Disease-free leaf litter can also be added to compost piles. Shredding leaves with a lawn mower speeds up decomposition by creating smaller pieces for organisms to break down. Compost piles should include equal parts of “brown” carbon-rich materials such as dry leaves or shredded paper, and “green” nitrogen-rich materials like fresh grass clippings or fruit scraps. A pile should ideally be two or three feet high when started.
Once a compost pile has begun decomposing, new material should not be added since it slows down completion. Regular turning—moving outside material toward the center—helps speed up decomposition; this should be done every few days initially and then weekly. The pile should remain moist but not wet.
With these methods, usable compost may be ready in several weeks to months. More information about backyard composting is available from resources such as UC Master Gardeners of Fresno County’s Backyard Composting (https://ucanr.edu/sites/mgfresno/files/276863.pdf) and California Sea Grant Extension and UCCE’s Composting (https://caseagrant.ucsd.edu/sites/default/files/Composting-2pg.pdf).
Residents with gardening questions can contact jmbaumbach@ucanr.edu with details and photos if possible.
