How to Start Composting at Home Without the Mess

Compost doesn't care what it sits in, as long as air can get in and excess water can get out. Plastic bins, tumblers, wire or wooden bins and a simple heap all work. The EPA notes that bins can be built from materials such as wire, wood and cinder blocks, so a bought bin is a convenience, not a requirement.

Match the setup to your space:

• Backyard: a tumbler or a three-sided wooden bin gives you room to add material and mix it.
• Balcony or patio: a lidded bin or a drilled storage tote keeps the pile contained.
• Kitchen counter: a small caddy with a charcoal filter in the lid holds scraps until you carry them out.

Whatever you choose, add plenty of ventilation holes if the container is solid plastic. A sealed container with no airflow tends to turn soggy and sour. A larger pile also holds heat better, so small bins usually break down more slowly. That is fine for a household's kitchen scraps, but expect to be patient.

Compost needs two kinds of material. "Greens" are wet and nitrogen-rich, such as fruit and vegetable scraps, coffee grounds and grass clippings. "Browns" are dry and carbon-rich, such as dry leaves, shredded cardboard and non-glossy shredded paper.

The EPA recommends adding at least two to three times the volume of browns to the volume of greens. Skip the browns and you get a dense, wet, oxygen-starved mass that smells bad. You don't need to measure precisely. The goal is to avoid adding wet scraps on top of wet scraps day after day.

Coffee grounds count as greens even though they don't look soggy, so cover them with browns too. A simple habit helps: keep a bag of shredded cardboard or dry leaves next to the bin, and add a handful every time you add scraps.

Treat the bin like a layered dish, not a trash can. Scraps left exposed on the surface attract fruit flies and can turn sour.

Start With a Carbon Base

Begin a new bin with a few inches of dry leaves or shredded cardboard. That base soaks up excess moisture from what comes after and leaves air pockets for airflow.

Bury Fresh Scraps, Don't Just Toss Them

Make a small hollow in the existing pile, add the scraps, and cover them with browns. The EPA's advice for keeping rodents away is the same: cover and bury food scraps in the pile.

If compost smells bad, moisture is a common cause, either too much or too little. The target is the consistency of a wrung-out sponge: damp enough to clump slightly when squeezed, but not dripping.

• Too wet or sour-smelling: mix in more dry browns and fluff the pile to let air in.
• Too dry and crumbly: add a little water or some wet scraps.

Heavy rain can soak an uncovered outdoor bin. Covering it so rain stays out, while air can still move underneath, helps. In humid weather you will usually need more browns than in dry weather.

Turning or mixing the pile from time to time speeds up decomposition and adds air. Once a week or every couple of weeks is plenty for most home setups, and the smell is a better guide than the look. Finished compost smells earthy, not sour or like rotten eggs.

Prevention works better than treatment. The EPA advises against adding meat, fish, bones, dairy or greasy foods to a home pile, because they can attract animals. Keep to fruit and vegetable scraps, coffee grounds, eggshells and similar plant material, and bury them under browns.

• Keep the lid shut. Animals are drawn by smell, so a bin that doesn't smell and has a secure lid avoids most outdoor pest problems.
• Keep the kitchen collection container small and empty it every day or two, so scraps don't sit and sour on the counter.
• With an open pile, add a fresh layer of dry material after every addition as a substitute for a lid.

A working pile doesn't need to look tidy. It can look matted or uneven partway through and still be doing well. What matters more is that it smells neutral and earthy.

Timing varies a lot. The EPA says compost in a well-maintained pile is usually ready in about three to five months, and an untended pile can take a year. A small bin fed only kitchen scraps may run toward the longer end.

If something goes wrong, treat the smell as the signal. A sour or rotten smell usually means too much moisture or not enough air. Add browns and mix it. That fix works far more often than starting over.

• U.S. Environmental Protection Agency, "Composting at Home"