It’s that time of year again. The recent freeze in Central Kansas means leaves are rapidly falling from deciduous trees and it’s a good time to stop and think about options for handling the litter. Although a scattering of leaves won’t harm the lawn, excessive cover prevents sunlight from reaching turfgrass plants.
Turf left with excessive leaf cover for an extended period will be unable to make the carbohydrates needed to carry it through the winter. Any newly planted turf will be especially susceptible to damage from a pile of matted leaves.
Leaves are too valuable to throw away. Here are two good options for dealing with the fallen leaves other than bagging them up and putting them out for the trash collector.
Composting is a great way to handle the leaf refuse. Compost can then be used in the vegetable garden and flowerbeds during future plantings. Leaves can be chopped with the mower and added to a compost pile or even spread directly on the garden to start the decomposing process. Leaves placed on the garden may need a little help to fully decompose by spring. Sprinkle some nitrogen fertilizer over them before tilling in as this will get the decomposition process moving to ensure decomposition by spring. Leaves applied in fall should be nearly completely rotted by spring planting time.
Check out these K-State Research and Extension composting resources for more information:
- Making Compost: A Beginner’s Guide
- The Composting Process
- Using Compost
- Quick Composting
- Composting Troubleshooting Guide
If you do not compost, you can mow leaves with a mulching mower and let shredded leaves filter into the turf canopy. (A side-discharge mower also will work, but it won’t shred the leaves as thoroughly.) This method will be most effective if you do it often enough that leaf litter doesn’t become too thick. Mow while you can still see grass peeking through the leaves.
Some folks wonder whether this practice will be detrimental to the lawn in the long run. Research at Michigan State University in which they used a mulching mower to shred up to about one pound of leaves per square yard of lawn (one pound is equal to approximately 6 inches of leaves piled on the grass) for five consecutive years, found no long-term effects of the shredded leaves on turf quality, thatch thickness, organic content of the thatch, or soil test results (pH, nutrients, etc.). If you mow leaves and have a cool-season lawn, be sure to be on a fall nitrogen fertilization program. Core-aeration can also help assist with the movement of leaf material into the soil if you are worried about too much litter. If you have a warm-season lawn, you can still use this technique but wait to fertilize and core-aerate until late next May or early June.
One final note
With concern rising over native insect and pollinator populations it can also be a good idea to leave some ‘wild’ areas in our home landscapes. Native bees and especially bumble bee numbers are in decline. These pollinators require undisturbed places and plants (old plant stems) in which to overwinter. By allowing a part of the landscape to collect a layer of leaves and remain unmowed throughout fall to spring and by allowing annual and perennial plant stems to remain standing during the winter we can begin to help these valuable insects survive and thrive from year to year.