What to do with autumn leaves?
Once again, it is that time of year. Farmers toil in the fields, families meander through corn mazes and neighborhoods prepare for masked and hooded goblins and superheroes. Windows flung open, welcoming the crisp, fresh air of autumn. Everything becomes pumpkin-flavored and… *cough, cough*
Oh, no! Close the windows! And yes, *cough* people start burning leaves.
Some municipalities do ban leaf burning. If you are leaf burner, this column is for you.
Burning leaves is a waste of energy. Locked inside that leaf are nutrients ready to recycle back into the soil. It took nature eons to build that soil and create a system of nutrient cycling. Trees pull that energy from the soil, use it in the process of making leaves (actually, used in all types of plant growth and development) and then the leaves fall to the ground, decompose and return that energy to the soil. Burning leaves robs the soil of that recycled energy.
So what is a homeowner to do with all these leaves? You can expedite that recycling of energy-rich carbon leaves back into the soil through composting. Compost is incredibly beneficial to soil of all types, especially heavy clay or sandy soils.
To compost leaves, gather them up in whatever way is most suitable. I put the collection bag on the mower and mow my yard collecting leaves along the way.
In a successful compost pile you need carbon and nitrogen, ideally at a ratio of 30:1, respectively. Carbon should be the bulk of your compost pile. Carbon is your autumn leaves. Nitrogen is the fuel of the composting process. Sources of nitrogen are lawn clippings, vegetable scraps, coffee grounds or any green living plant material. Some home composters use nitrogen fertilizer.
Air and water are the last two ingredients in a compost pile. The microbes whose job it is to break down the carbon-rich materials use air, water and nitrogen. By shredding the leaves, you increase the surface area for the microbes to bind to the material.
Composting materials should have the feel of a wet sponge. Turn your compost pile at least once a week for the first few months. Should a compost pile begin to smell, there is not enough air. Turning the pile will bring oxygen back into the center of the compost pile.
If composting sounds like too much work, then try my preferred way to handle autumn leaves. I gather the leaves using a blower, rake or mower. Then using a leaf blower, set to reverse, I shred the leaves and use them as mulch in my landscape.
Lesson 1 in leaf shredding – shred your leaves. Yes, some skip this step and just pile leaves around their plants. Whole leaves mat down, trapping excess moisture underneath or not allowing water and air through to the soil. Whole leaves also catch the wind easier and blow around more than shredded leaves.
Lesson 2 – Your leaf shredding device should have a metal impeller. Many leaf blower/vacuums have plastic impellers, which may break if any small pebbles or sticks accidentally are sucked up.
Lesson 3 – double shredding significantly reduces the volume of leaves. By running over the leaves with my mower and then running those shredded leaves through my leaf blower/shredder, I take a pile of leaves the size of a small car to a couple of five-gallon buckets.
Lesson 4 – If you have recurring foliar disease on your trees don’t mulch your leaves. Proper composting can break down those diseases. Removing the leaves from your property will also break the disease cycle.
Lawns benefit from shredded leaves too. Research from Michigan State University shows shredded leaves in the turf add organic matter and mulches bare patches of soil, blocking potential germinating weed seed.
Some organizations will take your autumn leaves, shred them and sell them back to homeowners. I happily relieve my neighbors of their bags of leaves. I even ask our Master Gardeners if they can spare some carbon. I am a bit of a leaf hoarder. Fortunately, it decomposes by the end of summer, and I’m left leafless, anxiously awaiting autumn.
Hopefully, if you’re a leaf burner, I’ve stayed the lit match in your hand this autumn. All soils benefit from compost, and nearly every yard needs mulch somewhere. Consider the underutilized source of autumn leaves to meet your soil’s needs.
by Christopher Enroth, Illinois Extension
