Composting at Home: Turning Kitchen Scraps Into Garden Fuel

Pick an approach that fits your space. A simple open pile in a corner of the yard works fine for large properties. A three-sided wooden bin or wire cage helps keep things tidy and retains heat. Tumbler composters — sealed drums that rotate — are a good fit for smaller yards or anyone concerned about pests. Whatever you choose, place the bin in a spot with partial shade, close enough to a water source that you can moisten the pile easily.

Compost needs two types of material to break down properly. Greens (high in nitrogen) include fruit and vegetable scraps, coffee grounds, fresh grass clippings, and plant trimmings. Browns (high in carbon) include dry leaves, cardboard torn into small pieces, paper bags, straw, and wood chips. A good starting ratio is roughly two to three parts browns for every one part greens by volume. Too many greens creates a slimy, smelly pile; too many browns slows everything down.

Start with a four-inch layer of coarse browns — wood chips or straw work well — at the base to allow airflow. Add a layer of greens on top, then cover with another layer of browns. Repeat this layering pattern until you have at least a cubic foot of material, which is roughly the minimum mass needed to generate useful heat. Chop or shred larger pieces before adding them; smaller particles decompose significantly faster than whole items.

The pile should feel like a wrung-out sponge — damp but not dripping. In dry weather, water the pile lightly every few days. In very wet weather, cover it loosely to prevent waterlogging. Turn the pile with a pitchfork every one to two weeks. Turning introduces oxygen, which feeds the microorganisms doing the work and prevents the anaerobic (oxygen-free) conditions that cause bad odors. Move material from the outer edges to the center, where temperatures are highest.

An active pile will feel warm in the center — sometimes noticeably hot. If the pile smells like ammonia, add more browns and turn it. If nothing seems to be happening, add more greens and check moisture levels. A pile that has gone cold and dense may just need turning and a handful of fresh kitchen scraps to restart microbial activity. Patience is part of the process: hot, well-tended piles can be ready in four to six weeks; slower, less-managed piles take three to six months.

Finished compost looks and smells like dark, crumbly soil — earthy, not rotten. You will no longer be able to identify the original materials. To harvest, stop adding new material and let the pile finish; then dig from the bottom or emptiest side, where decomposition is most complete. Mix two to four inches of compost into garden beds before planting, use it as a top dressing around established plants, or blend it into potting mix for containers. To understand how compost interacts with your native soil, see our guide to soil types.