Made in pile, hole, bin or barrel, compost might be the garden ingredient that puts the “beef” in a beefsteak tomato, the green in the collard or the snap in a pea.
And all it takes to make compost—converting food scraps and yard materials into rich, healthy soil—is a small space in the yard or any one of the many types of manufactured composting bins—plus a little effort on your part.
Soil made from composting has many advantages over the soil in your garden or yard that might be depleted of nutrients:
• You’ll water less—a nice benefit in the midst of drought—because compost absorbs and retains moisture.
• You’ll use less fertilizer because compost is rich in nutrients.
• Compost improves the structure of heavy clay soils as well as loose sandy soils.
• It makes plants healthier and therefore more resistant to disease and pests, reducing the need for herbicides and pesticides.
• Less watering, fertilizing and treating saves money.
Between 15 and 20 percent of the food supply in this country ends up in the household garbage can, according to Natural Resources Defense Council scientist Dana Gunders. That adds up to the equivalent of $2,275 a year for a family of four, plus the cost of energy and water used to produce, transport and prepare that food.
Food waste is the largest component of solid waste in landfills, Gunders says. There, it gets buried and breaks down mostly without oxygen to account for 23 percent of all U.S. emissions of methane, a greenhouse gas about 20 times more potent than carbon dioxide. In a compost pile, by contrast, food decomposes using oxygen, producing far less methane.
Composting reduces household trash volume, which could eventually mean fewer garbage trucks hauling to the landfill, lowering fuel use and emissions. A typical trash truck consumes about 9,000 gallons of diesel fuel per year, according to the Solid Waste Association of North America. Suzanne Pundt, a biology instructor at The University of Texas at Tyler who started composting because she loves to garden, cut her household trash volume more than three-quarters.
Texans send 5 million-plus tons of organic yard materials to landfills each year, too, paying roughly $3 million for the privilege, according to the Texas Commission on Environmental Quality.
Bin or Barrel
Although all that’s really needed to begin composting is a corner of the yard where you dispose of kitchen and yard waste in a pile or hole, Pundt chose a rotating barrel-style bin with an aeration system. “I wanted to be able to turn it easily, and I discovered that aeration helps the process go faster, so I wanted a system to do that,” she says. Alternately, McAllen resident and composter Nancy Millar makes compost for her lush tropical landscaping in a standing commercial bin because it takes up little space and isn’t noticeable.
A kitchen container to hold materials until you’re ready to take them outside comes in handy. This can be a jar or bucket, or something made specifically for collecting compost—anything large enough to hold at least a meal’s worth of scraps but small enough to keep handy. It should also be easy to clean and have a lid.
The Right Mix
Lou Kellogg, a master gardener and compost specialist with Texas A&M AgriLife Extension Service in Bexar County, says the proper balance of nitrogen, or “green” units, and carbon, or “brown” ones, is key. This is where most efforts go wrong, he adds.
A good rule of thumb is about one-third green and two-thirds brown by volume. Green, nitrogen-rich items include grass clippings and food scraps. Brown, high-carbon items include dry leaves, newspaper and cardboard. (See sidebar.)
Certain materials don’t lend themselves to compost. Meat, fish and dairy products will compost but also, unfortunately, attract critters. Weeds or invasive plants in your compost could spread their undesirable seeds, and most hay contains a weed killer that passes through horses unscathed, so hay in your compost could kill the plants on which you use it. Cow and chicken manure are OK, but cat and dog waste contain harmful pathogens. Nonbiodegradable materials such as plastic and metal won’t break down.
The right amount of moisture is also important: Too much can create odor, so compost that smells probably needs more brown units; too little moisture slows down composting. Pundt fills her bin with dry leaves, adds water to moisten, then regularly adds vegetable matter from the kitchen. “I take the lid off and eyeball it. It needs to be nice and moist, not sloppy wet, but not too dry.”
The microorganisms that break down materials and create new soil need plenty of surface area, so it helps to cut, break or shred components from the house or the yard before putting them in.
Those new to composting often worry about insects and other pests, but experts say that if you do things right, compost won’t attract any more pests than a typical yard or garden.
Burying food scraps under a layer of brown material (dry leaves or paper) and keeping the pile moist but not wet helps keep undesirable insects out of the bin. Turning the compost to create higher temperatures also kills fly larvae and weed seeds. A bin with a lid and bottom helps cut down on larger pests, such as opossums or raccoons.
Turn on the Heat
Turning compost isn’t necessary, but it adds air, breaks up clumps, and redistributes moisture and heat, a natural byproduct of organic decomposition. Methods for turning depend on the type of composting system you’re using—a shovel, pitchfork or rake works for a pile, while some manufactured units have built-in mechanisms to rotate the compost.
The best time to turn, Kellogg says, is when the compost is 140 to 160 degrees. You can measure this with a compost thermometer, available at many gardening supply stores. Or you can turn about once a week, says Daniela Ochoa Gonzalez, a planner with Austin’s Resource Recovery Department. Turning more than once a week disturbs the microorganisms and disrupts the process. If you don’t turn your compost at all, it will still compost, but it takes longer.
“I know you’re supposed to turn your compost, but Mother Earth doesn’t, so we just let it do its thing,” Millar says.
Finished compost is dark brown or black, has a crumbly texture and smells earthy. Have realistic expectations about how long compost takes and its appearance, says longtime home composter Kim Cook, who owns Exaco, an Austin-based company that sells compost bins and collectors. “Don’t be disappointed if it doesn’t look like the bags of compost you buy, which are manufactured,” she says.
Compost is most effective when used within six months, says Kellogg. When planting a garden, mix 1 to 2 inches of compost into the top 6 inches of soil. Sprinkle a one-quarter- to one-half-inch layer of compost on an established lawn or garden, and water. You can also use compost as one-third of a potting soil mix. The organic content of composted soil also provides nutrients for beneficial microbes and worms, which in turn make your garden even healthier.
Compost fans say the practice can take a little getting used to, but the end result—healthier plants and a healthier planet—make it well worth the effort.
Melissa Gaskill, frequent contributor