Monday, December 5, 2011

Breaking It All Down

This is going to be a totally rotten post. Ok, maybe it's just the topic that will be rotten. A few posts back, we told you about that lovely pastel compost bin made of dumpster fodder. Now it's time to talk about filling it up, and letting it rot.

First, a couple of composting basics. Compost is formed by the process of decomposition. During this process, bacteria that are found in nature feed on organic materials and turn them into humus, a fluffy, crumbly dark brown soil-like material that improves soil structure and moisture retention. Our goal then is to create an environment that will allow these bacteria to thrive. So what do the bacteria need? It's actually pretty simple: food, water, and air.

There are two basic types of food that any compost pile needs, commonly referred to as browns and greens. Browns are carbon-rich ingredients like dried leaves, cardboard, sawdust, wood chips, etc. Greens are nitrogen-rich ingredients like kitchen scraps, grass clippings, garden weeds, used coffee grounds, etc. A good compost bin needs the right mixture of both of these food sources. Bacteria really feast on the green material, but they need a good balance of brown material to keep the pile aerated. A pile with too much "brown" material won't decompose very quickly, but a pile with too much "green" material can get stinky. It may take some practice to get the balance right, but many internet sources suggest a ratio of 2:1 green to brown material by volume is a good starting point.

Greens: weeds, kitchen scraps, mushy Jack-O-Lanterns, and coffee grounds.

Browns: Shredded fall leaves.

The water part of the equation is much simpler. Don't keep the pile sopping wet, but don't let it dry out either. A good compost pile should be as moist as a wrung out sponge. Some people cover their compost bin with a tarp or scrap of carpet during the hot summer months to keep it from drying out.

And the final ingredient is air. You'll remember that we liked the used shipping pallets because they would allow air to flow between the slats. A good supply of air will allow your pile to grow lots of aerobic bacteria. These bacteria will quickly break down the material into fluffy humus and leave a pleasant, earthy smell. If the pile doesn't get enough air, the decompostion will be slow and you can start to notice a stinky rotten odor, caused by anaerobic bacteria. One of the best ways to incorporate air into your compost is to turn the pile with a pitchfork. The more often you turn a compost pile, the faster it will break down. It's a good idea to turn the pile at least every 7 to 10 days.

So there's the rundown of how to make compost. We've got to thank the folks over at Home Composting Made Easy for our rotten education. If you're interested in starting a compost bin of your own, you should definitely check our their website.

But how are we doing so far? Well, it could be better. We're pretty happy with our initial ratio of browns and greens, but we haven't been diligent about turning the pile or keeping it moist. We could probably also increase our bacterial growth if we added more material to the bin. We'll keep working at it, and we'll be sure to post more updates along the way!

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