One way that people could reduce burning would be to compost their leaves. Photo from Purdue University.

By Jeff Burbrink
Ag & Natural Resources Extension Educator, Purdue Extension LaGrange County

LAGRANGE — In a few days, the fall ritual of burning leaves will start, filling the air with smoke and leading to debates on social media and newspaper editorial pages about the good, the bad and ugly side of the issue.

Jeff Burbrink

One way that people could reduce burning would be to compost their leaves. For those who think composting is difficult, think again.

Compost, I am fond of saying, is nothing more than “organized rot.”

The basic ingredients to make compost work are brown materials (your leaves), green materials, water and air. It’s the green materials that are often in short supply if you didn’t plan ahead, but its easily remedied with nitrogen fertilizer.

First, find a place to pile the leaves. Put a layer of leaves that is 8 to 10 inches deep. Leaves are mostly made of carbon, and will not breakdown quickly without nitrogen. Add some grass clippings to supply that nitrogen. Put an inch or so of the grass clippings over the pile of leaves. Then continue to add layers of leaves and grass clippings.

Don’t have grass clippings? It is the nitrogen in the grass clippings that fuels the breakdown of the leaves. Think of nitrogen as the source of energy. If you do not have any clippings, use some cheap nitrogen fertilizer, like you would use on your lawn (with no insecticides or herbicides in it, of course).

Urea is another high nitrogen fertilizer that is relatively inexpensive and can substitute for the clippings. A cup or two of urea fertilizer spread over 25 square feet will substitute for the grass clippings.

After building a layer or two of leaves, clippings or fertilizer, add some water. It needs to be damp, but not running out the bottom of the pile. The water is used by the microbes in the pile to breakdown the organic matter.

Water also helps to distribute the heat within the pile. Add water every time you add a layer of leaves. You can make a compost pile as big as you want it, but generally when the pile gets over 4-5 feet tall, it gets unmanageable without some equipment, like a bucket loader.

How do you know the compost pile is working? The center of the pile is where the action is. The center will heat up, often to 130 to 160 degrees. You can feel the heat, and might even see some steam rise from the pile on a cool morning.

After 10 to 15 days, the pile will cool down. At this point, the pile has probably shrunk in size by 50%. The leaves on the interior of the pile will be very decomposed, while the outer portion of the pile will still look like leaves and grass clippings.

At this stage, you turn the pile. Form a new pile with the outer portions of the old pile, and put the mostly composted interior materials on top. As you do that, add some water, throw in a little fertilizer, and things will start cooking again.

On some occasions, things go wrong when composting. If the pile begins to smell, its generally too wet, or it has too much green (or fertilizer) in it. Add in some brown materials, remix, and it should start heating again.

If the pile does not heat up, that means there is not enough green matter (grass clippings or fertilizer) in the mix to fuel the composting, or the pile may be too dry. Add some green materials and some water, remix, and your pile will likely heat up in a day or so.

I’ve been composting leaves for 30 years, and found it to be a simple process. My kids often speak about how dark and rich the compost is when they are helping me plant vegetables and flowers in the spring.

Want more information on composting or how to use the compost in your landscape? Visit tinyurl.com/bddbp49b to see Purdue’s publication on the subject.