URBANA, Ill. – For the typical home gardener, fallen leaves are one of the most readily available forms of organic matter and serve as a wonderful soil conditioner, said University of Illinois Extension horticulture educator Nancy Kreith." After raking leaves this fall, think about recycling them on your property rather than bagging them for curbside pickup," Kreith said.
Increasing organic matter (OM) in the soil will increase the amount of microbial activity that includes beneficial bacteria, fungi, and other microorganisms that aid in plant growth, Kreith explained. "OM coats finer clay particles in the soil, providing more air space, and binds sandy soils allowing for better water retention. Ideal garden soils should test at 5 percent OM," she said. A standard soil test will provide the percentage of OM in the soil. Contact a local U of I Extension office for information on soil testing kits and labs.
Brown leaves can be used as a carbon-rich material to add to a compost pile or they can be shredded and used as mulch. Kreith suggests running the lawn mower over raked leaves to cut them into smaller pieces or using a leaf shredder or leaf mulcher as an alternative. "This initial breakdown allows for improved air circulation and more surface area for quicker decomposition," she said. Kreith added that diseased leaves should be separated from the leaves that will be recycled or composted. The rate of decomposition for leaves will depend on the leaf size, tree species, and moisture level. Brown leaves break down faster if they are shredded and moistened. If unshredded leaves are applied as mulch, they tend to mat together and suffocate the soil and/or vegetation," Kreith said. "However, having matted leaves in a vegetable or annual garden bed in the fall will help smother winter annual weeds, and during the next spring, the leaves can be incorporated or tilled into the soil," she added.
Another easy way to recycle leaves is by storing them in garbage bags with small holes throughout the bag surface, which allows the leaves to break down naturally. "Wetting the leaves and having holes in direct contact with the earth (where more microbes are present) will speed up the decomposition process," Kreith said. "The end result is referred to as leaf mold (partially decomposed leaves). Leaf mold can then be used as mulch or saved as a carbon source for adding to your compost pile in the summer when there are less readily available 'brown' materials." Brown or dry materials are typically high in carbon and will help to balance the "green" or wet nitrogen-rich materials that are added to a compost pile, she added.
"By recycling leaves on your property, not only will you be improving your garden soil, you will also be making an environmentally conscious choice to keep your yard waste onsite rather than having it hauled off as waste," Kreith said.To learn more about the basics of composting, visithttp://web.extension.illinois.edu/homecompost/intro.cfm.