Leaves. Useful to the tree. Great for jumping in. Not much fun to clean up. Find out what you should be doing with those leaves to let them help you and your landscape in the long run.
Once the leaves fall to the ground, they can become a big headache. It may seem like a good idea to let all of the leaves fall, then pick them up all at once, but this isn’t the best practice. If the leaves get too deep on top of the turf, they can actually smother the lawn. Rake or mow leaves into the turf on a regular basis to avoid build-up of leaves on lawns which can suffocate turf or increase the risk of snow mold disease.
No need to make it difficult, use the lawnmower to do the work for you. Pulverize leaves by using a mulching mower or making 2-3 passes with a regular mower. After mowing, the pulverized leaves should not cover the turf, but filter into the grass. Up to 6” of leaves can be mulched at a time, depending on the type of mower that you have. Push mowers will handle smaller amounts of leaves, but are still very effective. Consider alternating between bagging and mulching leaves, especially if you have a lot of leaves that collect. Finer pieces of leaves can be added to the compost bin, worked into the garden, or allowed to infiltrate into the lawn. They also make good mulch in landscape beds and good winter protection for the more tender perennials. Covering the bare soil with ground leaves will help prevent winter annuals from germinating and they also decompose into good organic matter for the soil.
In addition to getting rid of the leaves, mulching them into the lawn has additional benefits to the turf. Research has shown that there are several benefits to mulching leaves into the turf. Spring green up can be achieved with less fertilizer in years following mulching leaves into the turf. Fewer weeds the following year is another benefit to mulching leaves into the turf. The decomposing pieces of leaves cover up bare spots between turf plants that are usually excellent spots for weed seeds to germinate. Michigan State University research has shown nearly a 100% decrease in dandelions and crabgrass germination following the adoption of mulching leaves into the turf after just 3 years.
Leaves can also be saved for next year. When dry, leaves can be saved in plastic bags to use as a source of carbon in next years’ compost pile. In a good compost pile there should be equal parts of carbon, brown plant material, and nitrogen, green plant material. Often during the growing season, only high nitrogen plant material is available. By saving your fall leaves now, you can help to ensure the proper carbon to nitrogen ratio for your compost pile. The leaves will decompose more quickly if they are chopped or mulched into smaller pieces, but it is not required in order to put them into the compost pile. The main concern is to make sure that the leaves you are using in the compost pile are not diseased. Most compost piles are not able to reach proper temperatures to kill many of the pathogens.
Water pollution is another potential problem with tree leaves. Leaves that wash into streams, lakes, and ponds can contribute to water pollution. If an abundance of leaves are allowed to decompose in the water, this can lead to impaired water ecology, commonly seen as excess algal growth. To reduce the pollutant load on surface water, do not dump tree leaves or grass clippings along stream banks or near ponds where rain fall and snow melt can carry them into the water.
Rake them. Mulch them. Compost them. Let leaves work for you.
Elizabeth Killinger is the Horticulture Extension Educator with Nebraska Extension in Hall County. For more information contact Elizabeth at firstname.lastname@example.org, her blog at https://huskerhort.com/, or HuskerHort on Facebook and Twitter.