A local friend just contacted me to ask who takes care of our leaf removal, so I told her: nobody. Ever since moving to the suburbs, I’ve had to take care of a lawn, and one of the first shortcuts I discovered was the little-known option of mulching the annual deluge of leaves. I just keep mowing the lawn every two weeks until the trees seem to have finished shedding, and let the leaf shreds decompose into the turf.
I’ve been doing this for a few years now, first on a lightly wooded lot and now on a very heavily-wooded one, and it’s been working fine. Don’t take my word for it, though, look at the science:
Studies in Michigan were conducted in the 90’s to evaluate the effects of leaf mulching on turf, under varying conditions. The first study considered three different leaf application rates (none, 3 inches, and 6 inches) of mixed tree species, mulched in with a rotary mower using two passes in October. It also considered 2 different N applications (2 or 4 lbs nitrogen/1,000 sq ft). A second study used leaves from maples or oaks … Michigan State scientist[s] did note that while the N application improved the turf quality rating, it did not seem to speed the decomposition of the leaves. It was also pointed out that chopping leaves into small particles was important and allows them to filter into the turf canopy making soil contact.
In a 1998 study at Michigan State, soil [samples] from these various plots were analyzed. Soil pH did not change, but organic matter did increase in response to the leaf mulching. Composition of the grass clippings was also affected; the percentages of carbon and nitrogen both increased with leaf mulching, but the ratio of carbon to nitrogen stayed constant, which is positive.
So even with six inches of leaves, two passes of the mower in October was all the “leaf removal” the lawn needed, and the grass actually benefited from this treatment. Just to be sure, though, the folks in Michigan did a follow-up study in which they covered turf plots with up to 18 inches of leaves before mowing them in. The lawns still did fine. Researchers at Purdue University did a similar study, with similar results.
Leaf removal is to lawncare companies what Christmas is to retailers, though, so these decade-old studies are still pretty poorly publicized. For the past month, my neighbors have all been running their leaf blowers and writing big checks to landscapers to haul away perfectly good lawn food. I just keep on mowing.