Fall is a good time of the year to build your compost pile, as I mentioned in this column two weeks ago. Here is how to go about creating “black gold” for your garden next spring.
First of all, the compost process is a bit of art and a bit of science. The science is the materials necessary for composting to occur. The art is to put these materials together in order to speed up the composting process.
To create a working compost pile, you need brown stuff (carbon), green stuff (nitrogen), water and air.
Once these materials are mixed together, bacteria work to break down the plant tissue, soon joined by fungi and protozoans. Other small insects, springtails, mites and earthworms also play a role in breaking down the plant debris.
Carbon (brown stuff) and nitrogen (green stuff) are needed by the microorganisms. Brown stuff is woody material or dried leaves. Green stuff is grass clippings and other green lawn waste.
Start your pile by selecting a location that can be kept fairly dry and that is close to the garden for easy access. You can either use a prefabricated compost bin or create your own with chicken wire or other type of material to build the sides.
The size of the pile should be around 3 by 3 by 3 foot by 5 by 5 by 5 foot. If you create a pile that’s much larger and can’t be turned easily, you won’t have sufficient oxygen in the center of the pile for the compost process to occur.
Begin the pile by layering 4 inches of brown stuff and then 4 inches of green stuff. Make sure the first layer is somewhat course and doesn’t compact flat to the ground. After the green layer, add a shovel full of either soil or already finished compost. This provides the necessary microorganisms to do the work.
Add a cup of high nitrogen fertilizer to this brown/green layer. The fertilizer provides additional nitrogen for the microorganisms.
Wet this layer down with the hose, creating the feel of a damp sponge. Continue repeating layers until you are at the top of the pile.
When these materials are mixed in the right proportions and the bacteria begin working, the center of the pile should heat up to around 140F. The pile will actually decrease in size or “settle” if the process is working.
Once this temperature drops, the process in the center is finished and the pile should be turned. This will allow for the other materials to be moved into the center of the pile and worked on by the microorganisms. You may have to turn the pile several times to finish all of the materials.
As I mentioned, if all of the materials are in the right combination, the compost process increases. However, if they aren’t, the process slows down. You will eventually get compost, but it may take longer.
Chopping up the materials into smaller pieces increases the surface area for the bacteria to work on. Run the woody material through a chipper-shredder if you have one. Run the lawn mower over the green stuff to chop it up somewhat.
I like to create a compost pile in the fall because you can collect the leaves and grass clippings together and mix them into the pile.