With the temperature hovering in the low 20s and a few snowflakes drifting through the air, it probably looked odd that I was out in my yard on the lawn mower. The grass had long gone dormant, the ground was already frozen, and the path behind me sparkled when the sun peeked out and lit up the ice.

Oak leaf in mowed leaves
Mowing leaves in a constant direction eventually turns foliage into small bits of short-term mulch. (One full-sized oak leaf gives this example some scale.)
Photo Credit: © Pennystone Gardens
Small mounds of leaf mulch
Freshly mowed leaves create small mounds in critical areas. By spring, they’ll have collapsed into nice, compact mulch.
Photo Credit: © Pennystone Gardens
Mountain Laurel in leaves
Mountain laurel is quite fussy about mulch, but the acidity of oak leaves and the chemical composition create a perfect slow-release fertilizer for it.
Photo Credit: © Pennystone Gardens

But I wasn’t mowing the grass – I was actually mowing leaves.

Where I live, trees shed leaves in three major waves. The maples are first: vivid yellows and reds, thin and papery and very quick to decompose. Next come the huge brown, crunchy chestnut oak leaves, eager to poison the soil where they land and smother the ground. (Oaks are territorial plants and just don’t care for competition. The toxic nature of the leaves dissipates quickly and then settles in to form a dense mat. At the lowest half-inch, the leaves decompose to form brown humus that eventually feeds the tree looming above.) A couple of weeks later, and usually after the first real warning that winter is coming, the foliage stragglers – the red oak leaves – swarm across the blustery ground.

In an ideal world, none of these leaves would be raked, gathered, discarded or, in my case, shredded. While they’re the worst possible thing for lawns and flower beds, in their natural state, leaves are a critical part of a forest ecosystem. They serve as mulch, fertilizer and habitat for useful creatures that help keep trees strong and healthy.

But to many gardeners, fall leaves are like moss: evil, annoying and a problem to be dealt with ruthlessly. They offend our sensibilities of neatness and order. After all, if we left them work in their natural way, the back yard would revert to the sort of place to which we drive many miles to visit, hike in and admire the splendors of nature.

So we rake leaves. But then what? For a long while, it was fashionable to rake fall foliage into piles and set them on fire, making people cough – and sometimes burning far more than planned. Then we started to fill huge plastic trash bags (sometimes in the colors of Halloween jack-o’-lanterns), which were then trucked off to landfills.

More recently, it’s become trendy to whisk those leaves curbside so the community road department can come along with a giant hose and impeller to haul them off to someplace other than our lawns. These are often communities where one man’s waste is another man’s treasure. Piled up off to the side, these leaves eventually decompose into fabulous compost eagerly gathered in the spring to improve gardens.

All of which brings us back my option of what to do with all the fallen foliage: mowing leaves in precise patterns. By the end of the year, the ol’ mower blade is getting dull, but it’s still fine for small twigs and leaves. The excursion works kind of like a leaf blower, except that the leaves are continually ground up into tiny bits. If you drive your mower right, you’ll blow your newly mulched leaves into convenient piles to either leave in place or collect with a hayfork. Some mowed leaves can go directly onto flower beds, just an inch or so deep, to provide a good winter mulch. Some can be saved to be brought out in spring to provide an inexpensive alternative to purchased wood chips (or other store-bought material).

And by the time the leaves come down again next autumn, this year’s collection will have turned into a fresh layer of humus, rich and useful to a thriving garden. This simple practice of sustainability means what used to be an unwelcome fall chore is now a major part of the gardening process.

I sometimes feel a bit guilty about depriving trees of their lunch, so I leave some around the base of the tree. (I’ve also abandoned feeding many areas of lawn – an uphill battle in a woodland setting anyway – but I keep mowing to encourage an expanding field of moss. But that’s another sustainability issue!) With the trees well-fed and my beds well-mulched, I can finally winterize the mower for the season, knowing that I’ve used those fall leaves almost as nature intended – and saved myself a few bucks along the way.