How to Make Compost
Learn about the simple ingredients and processes that allow you to make great garden compost at home.
Two-Compartment Wooden Compost Bin
SH06E111DIYGARDENER May 8, 2006 _ Composting occurs in nature constantly. Plant and animal waste breaks down into soil-like particles over time, with no involvement from us. The simplest compost piles are just that _ piles of yard waste and kitchen scraps. There are no fancy systems, containers, bins or compartments to facilitate the process. (SHNS photo courtesy of DIY Network)
Home composting is a process that uses natural decomposition to transform landscape and kitchen waste into a rich soil amendment that does wonders for a garden. Decomposers, like bacteria, fungi, insects, nematodes, earthworms and other composting critters, are a composter’s best friend. As soon as plant material begins to decay, decomposers arrive to speed up the process. It’s helpful to know a little about these often unseen workers, because when they’re happy, they eat, and when they eat, compost happens.
Your compost pile needs four ingredients to become a home for decomposers: carbon, nitrogen, moisture and air. The first ingredient, carbon, which can be found in fall leaves, straw, woodchips, recycled paper and cardboard. Tree care companies are often charged a fee to dump their woodchips in landfills, and they may welcome an opportunity to donate some material to a home composter. Be sure that you have enough space for a load of woodchips that can be easily accessed by a large truck. Specify the exact number of loads you need, or you may come home to a mountain of woodchips in your driveway!
Microscopic decomposers need nitrogen to help them break down the carbon. Nitrogen comes into the pile in the form of green plant tissue. This can be freshly cut grass clippings, hedge clippings, vegetable kitchen scraps, coffee grounds, tea bags, juice pulp, spent annual plants, or finished manure from vegetarian animals (that’s chickens and cows rather than cats and dogs). As bacteria use nitrogen to break down carbon, they release heat. Heat is a good thing because it speeds up decomposition.
Dry material resists decomposition, and earthworms, fungi and bacteria need moisture to live. To make compost, the pile needs to stay damp. Sprinkling water as you add each layer of ingredients to your bin is a good way to make sure your pile starts off with the right moisture level.
On the other hand, swampy conditions can drive air out of the pile. Some of the most helpful composting bacteria (psychophiles, mesophiles and thermophiles) need oxygen to work. If the pile is too wet, or if it isn’t vented or turned regularly, they may run out of enough oxygen to stay alive and keep eating. Add air by turning your homemade compost with a pitchfork or poking holes deep into the pile with a pole or stick.
By adding the four essential ingredients, you’ll provide the sort of environment that supports the decomposers that make compost. But how do the decomposers find their way into the bin? Some people have the “If you build it, they will come” philosophy when it comes to introducing composting organisms. Others purchase bacterial and fungal spores to inoculate their bins. An easy, effective way to introduce the critters that make compost happen is to sprinkle some finished compost or garden soil into a new pile of fresh ingredients.