Start with a bin or pile and layer brown and green materials

You make compost by stacking layers of dry materials (brown) and wet materials (green) in a bin or on the ground, then letting bacteria and fungi break them down over weeks or months. The simplest method is a pile in your yard with no bin at all — just a designated spot where you layer leaves, grass clippings, and kitchen scraps. A bin speeds up the process and keeps rodents out, but it is not required. Either way, the same rule applies: alternate layers of carbon-rich brown materials with nitrogen-rich green materials, keep the pile moist like a wrung-out sponge, and turn it occasionally to speed decomposition.

The finished product — dark, crumbly, and earthy-smelling — takes anywhere from two months in a hot, actively managed pile to a year or more in a passive pile you leave alone. Most home gardeners see usable compost in four to six months if they turn the pile every week or two.

Key Takeaways

  • Brown materials (leaves, straw, shredded paper) provide carbon; green materials (grass clippings, vegetable scraps, coffee grounds) provide nitrogen — you need both for compost to break down.
  • A working pile should feel as moist as a wrung-out sponge and smell earthy, not rotten; if it smells bad or attracts flies, you have too much green material or it is too wet.
  • Turning the pile with a fork every week or two speeds decomposition to two to four months; leaving it untouched takes six months to a year.
  • Never compost meat, dairy, oils, or diseased plants; these either attract pests or spread plant diseases to your garden.

Gather brown and green materials in the right ratio

Brown materials are dry, carbon-rich items: fallen leaves, straw, shredded newspaper or cardboard, wood chips, and sawdust from untreated wood. Green materials are wet, nitrogen-rich items: grass clippings, vegetable and fruit scraps, coffee grounds and tea bags, plant trimmings, and fresh manure from herbivores (horse, cow, chicken). Aim for roughly three parts brown to one part green by volume — this ratio keeps the pile from becoming a soggy, smelly mess while providing enough nitrogen to heat up and decompose quickly.

Collect brown materials in fall when leaves drop, or save shredded paper and cardboard year-round. Green materials come naturally from your kitchen and yard — save vegetable scraps in a container on your counter and empty it into the pile once or twice a week. If you do not have enough green material, the pile will decompose slowly but still work; if you have too much green, it will smell like ammonia or rotten eggs and attract flies.

Build your pile or bin in layers

Start on bare ground or in a bin with a 4- to 6-inch layer of brown material — this creates air pockets at the bottom. Add a 2- to 3-inch layer of green material on top, then repeat: brown, green, brown, green. Aim for a pile at least 3 feet tall and 3 feet wide; smaller piles do not heat up enough to decompose quickly. If you are using a bin, follow the same layering pattern until the bin is full.

Water each layer lightly as you build so the pile feels moist throughout — not dripping wet, but not dry either. If you are using a bin with a lid, close it to trap heat and moisture. If you are building a pile in the open, you can cover it loosely with a tarp to keep heavy rain out, but air flow matters more than staying dry.

Keep the pile moist and turn it regularly

Check your pile once a week by pushing a stick into the center and feeling it when you pull it out. The pile should feel as moist as a wrung-out sponge — if it is dry, add water with a hose; if it is soggy and smells like ammonia, add more brown material and turn it to add air. The center of an active pile heats up to 130 to 150 degrees Fahrenheit as microbes work, so do not be alarmed by steam rising from it on cool mornings.

Turn the pile every 7 to 14 days using a garden fork or shovel: pull material from the outside edges (which are cooler and less decomposed) toward the center, and move material from the center outward. This mixes the pile, adds oxygen, and speeds decomposition. If you turn weekly, you will have usable compost in 6 to 8 weeks. If you turn every other week, expect 3 to 4 months. If you never turn it, the pile will still decompose but may take 6 months to a year.

Recognize when your compost is ready to use

Finished compost is dark brown or black, crumbly, and smells like rich soil — not like the materials you put in. You should not be able to identify individual scraps or leaves. If you see whole pieces of material, the compost is not ready; either wait longer or turn the pile more often to speed it up. A straightforward test: grab a handful and squeeze it; it should hold together briefly, then crumble apart when you poke it.

You can start using partially finished compost once the bottom layer is dark and crumbly, even if the top still has recognizable material. Sift it through a 1/2-inch screen or your fingers to separate finished compost from chunks, and return the chunks to the pile to finish breaking down. Most gardeners find they have a usable batch every 3 to 6 months once they get into a rhythm of adding materials and turning regularly.

Avoid materials that slow decomposition or attract pests

Never add meat, fish, bones, dairy, oils, or fats — these decompose slowly, smell terrible, and attract rats and raccoons. Do not compost diseased plants, weeds with seeds, or pet waste; disease spores and weed seeds can survive the pile and spread problems to your garden. Avoid glossy or colored paper, which may contain chemicals, and treated wood or sawdust, which can leach toxins.

Citrus peels, onions, and garlic decompose fine but can slow the pile slightly because they are acidic and pests dislike them — use them sparingly or bury them deep in the pile. Bread, pasta, and grains are safe but attract rodents if left on top, so mix them into the center. Pine needles and conifer leaves are very slow to break down; use them sparingly or skip them if you want faster compost.

Choose between a bin and an open pile based on your space and patience

An open pile requires no equipment and works anywhere you have 3 by 3 feet of ground space. It is slower (6 months to a year for finished compost) and more exposed to rain, pests, and neighborhood complaints, but it is free and straightforward. A wooden bin made from untreated lumber or pallets costs $20 to $50 and keeps the pile neater and warmer. A plastic or metal bin costs $30 to $150, heats up faster, and keeps rodents out completely — these are best if you live in a neighborhood with strict rules or active pest problems.

Tumbling bins (rotating drums on a stand) cost $100 to $300 and produce finished compost in 4 to 6 weeks because turning is built in, but they hold less material and require more effort to load and unload. For most home gardeners, a straightforward wooden bin or open pile works fine. Start with whatever you have or can afford; you can always upgrade later.

Frequently Asked Questions

Can I compost in an apartment or small space?

Yes, using a small bin or bokashi bucket on a balcony or in a closet. Bokashi uses special bran to ferment scraps in an airtight container over two weeks, then you bury the fermented material in a garden or potted plant. Traditional compost piles need more space and air flow, so they work better outdoors.

Why does my compost smell like rotten eggs or ammonia?

Too much green material or too much moisture creates anaerobic (airless) conditions where bacteria produce foul-smelling gases. Add brown material, turn the pile to add oxygen, and let it dry out slightly. The smell should fade within a few days of turning.

How do I keep rats and raccoons out of my compost?

Use a bin with a tight-fitting lid and bury food scraps under 6 inches of brown material so they are not visible. Never compost meat, dairy, or oils. If pests are already present, stop adding green material for a week and turn the pile daily to heat it up and make it less attractive.

Can I use compost that still has chunks in it?

Yes, partially finished compost works fine in gardens and potted plants — the remaining chunks will continue breaking down in the soil. Sift out large pieces if you want a finer texture for seed-starting or top-dressing, and return them to the pile.

Do I need to add compost starter or special microbes?

No. Soil, leaves, and grass clippings already contain billions of microbes that will start decomposition on their own. Commercial starters are not necessary and do not speed up the process significantly — proper layering, moisture, and turning matter much more.