One of many possible types of composting structures. Welded wire fencing surrounds the back and sides. (Photo by M.H. Ferguson)
(News article for August 20, 2019)
My mom says that while she didn’t grow up during the Great Depression, she was raised by people who did. She has maintained an aversion to waste that I have inherited from her as well as my dad.
When the leaves started to fall from the numerous oak trees at my house last fall, raking leaves and placing them in bags on the curb or burning them were not serious considerations. These take a useful resource and either put it in a landfill or send it up into the air as particulate matter, hydrocarbons, and carbon monoxide.
Thankfully, I had some materials left over from my days of trying – ultimately in vain – to keep my dog in my Baton Rouge yard. With some welded wire fencing and U-posts, along with a post driver that a neighbor kindly let me borrow, I was able to put together a roughly 20-feet wide, 6-feet deep, and 4-feet tall composting area on a Saturday last fall.
Then, the collection of leaves began. It was piecemeal, done when I had some time after work, and incomplete – there were plenty of leaves left on the yard and ultimately cut up with a lawn mower. But there were plenty of leaves to fill the bin to the point that leaves spilled out of the open side.
I continued to collect food scraps – coffee grounds (probably the largest part of my “food” wastes), egg shells, that spinach that I let go bad, etc. – in a tub in the fridge and add these to the compost bin from time to time.
Composting doesn’t have to be all that complicated. You don’t need any one type of structure to do it. In fact, you don’t have to have a compost bin at all. One of our composting fact sheets addresses composting with a “compost mound.” If you want to do vermicomposting (composting with worms), you can even do it indoors.
Composting depends in part on microscopic organisms (bacteria and fungi) to break down organic materials into organic matter that can then be used to enrich garden soil. So you need to feed those microbes.
In addition to water and oxygen (there are exceptions to this, but we’re going to talk about aerobic, or oxygen-requiring composting), those microbes need roughly 25 to 30 times as much carbon as nitrogen. So when we talk about what to put in a compost pile, we talk about carbon-to-nitrogen (C:N) ratios.
“Brown” materials, like fallen leaves, have relatively high C:N ratios. “Green” materials, like fruit and vegetable scraps, have relatively low C:N ratios. You need some of each for composting to occur in a timely manner.
One problem that sometimes occurs is that people only put food scraps or only put yard waste in a compost bin. This can result in a compost pile in which things don’t break down for a long time, since the microorganisms that would do the work don’t have what they need.
If you don’t have trees that drop their leaves in the fall, there are other “brown” materials that you can use. You can shred paper or even cardboard. If you do this, you won’t need as much, by weight, as you would of leaves, since paper and cardboard have higher C:N ratios than fallen leaves do.
Turning a compost pile is important for mixing “brown” and “green” materials and for even distribution of moisture and oxygen. If you don’t turn a compost pile, the materials will still decompose eventually, but it will take longer.
The LSU AgCenter has quite a few resources related to composting. The most comprehensive among the more recent publications is one called “Backyard Composting: Waste to Resources.” I like an older one titled “Basic Principles of Composting: What is Composting,” because it has a fairly extensive list of the types of materials that can go into compost piles, along with their approximate C:N ratios.
In addition to these, there is a series of publications in the Backyard Composting series on different types of composting structures: Cinder Block Bin, Cinder Block Multiple Bin, Compost Mound, Composting Mulch, Garbage Can Composter, Wire Mesh Bin, Wooden Box Bin, Wood and Wire Three-Bin Turning Unit, and Worm Composting Bin. These are available on our website (https://www.lsuagcenter.com).
Contact Mary Helen Ferguson.