Cecilia Nasti is an organic food gardener and enthusiastic home cook. She produces and hosts the weekly radio feature Field & Feast broadcast on public radio in Austin, Texas. A nature lover, she also produces and hosts Passport to Texas, a daily statewide radio series about the outdoors for Texas Parks and Wildlife.
My vegetable garden is getting a makeover this spring, and one of the things I'm most excited about is the soon-to-be built compost bin.
The formula for making compost is a simple 2:1 ratio of carbon to nitrogen. Carbon (brown) includes fallen leaves, wood chips and egg shells. Nitrogen (green) includes fresh grass clippings, manure, and kitchen scraps, but no meat, fat or bones as the compost may not get hot enough to kill harmful bacteria that may grow on those items. When you water everything and give it a good mix, the brown and the green break down and become "black gold."
Location. Find a sunny to partly shady place outdoors for your compost pile or bin. Ensure it's away from foot and pet traffic, and near your garden and a water source.Free range or contained. A free-range compost pile is easy to access and aerate. Sometimes, though, containing the pile is the better choice (if you need to keep kids and pets out of it, for example). You can find a wide variety of free plans for making compost bins, or find ready-made devices, including some that tumble and others that roll online.
The size of things. Aim for a compost heap that's 4'x4'x4'. That size is manageable, and offers enough volume for the pile to generate an internal temperature of between 120 to 150 degrees Fahrenheit. The high temperature stimulates growth of heat-loving bacteria that promote decay, which is what you're after. When the materials break down, that's when the nutrients become available to the soil, and ultimately to the plants.
Bacteria's buddies. Microbes, insects and worms also play a role in the decomposition of the compost pile. Worms are especially beneficial, as everything they eat comes out seven times more nitrogen-rich than when it went in. You can skip the compost pile altogether and focus on vermiculture, or worm composting. It just takes some red wrigglers, a ventilated container, bedding material like shredded newspaper, and food scraps. The worms and other microorganisms convert the entire contents into rich humus. In some cases you’ll have useable worm castings in just one week.
Water and aeration. You'll want to keep the compost pile moistened but not wet, and turn everything at least once a week. This hastens the decomposition process.
Problems and their solutions. If your compost pile is not decomposing quickly enough it may have too much carbon, not enough moisture, or needs to be turned more often. If it is stinky and getting slimy, it is too wet, or has too much nitrogen. Hold off on the water and add more carbon.Are we there yet? Compost is done when is has a rich, crumbly texture and an earthy smell. During fall and winter it could take months for it to decompose. During the heat of summer, you could have finished compost in a few weeks. Test doneness by reaching into the center of the pile and remove a handful of the compost. Put it in a self-sealing plastic bag and leave it at room temperature for a week. If when opened it smells like soil, it is ready. If it has a sour smell, it needs more processing.
The simple act of combining leaves, grass clippings and food scraps and transforming them into free, organic fertilizer is the ultimate in recycling. When compost is done, it looks and smells earthy, but what it does for your plants is heavenly.
Do you think you might attempt making compost? What do you see as your greatest hurdle?
Originally published March 31, 2014.