I have mentioned compost in most, if not all of my columns, so I guess it’s time to actually write about compost. I will admit right up front that I am a lazy composter. I know the theory and the science, of which dozens of books and magazine articles have been written, but when it comes right down to it I employ the least labor intensive method in my composting. I do what is classified as cold composting, and that is in relation to hot composting. Before I get into the details of these two methods, let’s do a little background education.

Compost is the bedrock of every good organic garden and farm. Nothing beats it for improving soil texture, drainage, water holding capacity, adding nutrients and supplying beneficial microorganisms to the soil, increasing root development and helping to prevent weeds and diseases. Wow, that is quite a feat for any one component to deliver! That’s why compost is so well researched and written about. It really is a magic bullet. So let’s get into it.

Air + water + carbon + nitrogen = Compost

Once again when we are talking about the garden we are talking about soil, and when we are talking about soil we are talking about soil microorganisms. That’s who needs the above ingredients to do the magic of changing raw materials into garden gold. There are two types of bacteria that work on decomposing organic matter, some need air and are called aerobic and other don’t need air and are called anaerobic. You want to encourage the aerobic bacteria to colonize your pile otherwise you will have a really stinky pile that will take a long time to break down. Air needs to get into the pile. This is usually accomplished by turning it every so often and layering materials to minimize compaction. For example you wouldn’t want to dump a bunch of grass clippings directly onto the pile because they will mat down. It would work better to mix the clippings with dry leaves or shredded paper or some other brown material. This keeps the pile fluffy allowing air to penetrate.

Water is another critical component. Your goal is to keep the pile moist like a wrung out sponge. Too much water reduces airflow and temperature and makes the pile smell. Too little water and decomposition slows down and prevents the pile from heating up. We will talk about heat later, but for now just know that it is a good thing.

Carbon is the stuff that all organic things are made of and it is used by the microorganisms as an energy source. Carbon materials are considered dry and brown or yellow and include things like, straw, dry leaves, pine needles, wood chips, sawdust, shredded paper, corn stalk and the like.

Nitrogen is another component of organic things and it is used by the microorganisms to create protein that they need to build their bodies. Nitrogen materials are considered wet and green, although they can be brown too, and these include things like grass clippings, green leaves, garden weeds and damaged veggies, seaweed, manure, kitchen scraps and coffee grounds.

Every recipe calls for a certain ration of ingredients and compost is no different. So far we know we need plenty of air and enough water to keep the pile moist but not soggy. Carbon and Nitrogen have their own special designation called the carbon: nitrogen ration. This is the amount of carbon and nitrogen needed to get the maximum decomposition in the least amount of time. This has been determined to be 30 parts carbon to 1 part nitrogen. I know this can be confusing but think of it this way 1 part green to 2 parts brown. Too much nitrogen and the pile will stink; too much carbon and the microbes won’t have enough nitrogen for their population to expand, once again slowing down decomposition. Remember it’s all about the microorganisms.

Ok, let’s leave it there for this week. Next week I’ll talk about hot and cold composting and few of the more trendy methods of composting.