Start with a location and a container choice

A compost pile works best in a spot that gets partial sun — four to six hours a day — and sits on bare soil or grass, not concrete. The soil lets worms and microorganisms move in from below. Choose a spot away from your house if you want to avoid smell and flies, though a well-maintained pile produces almost no odor.

You can compost in an open pile on the ground, in a wooden bin you build yourself, in a plastic tumbler, or in a wire cylinder. Open piles are free and straightforward but take longer to break down and attract more pests. Bins and tumblers speed decomposition and keep animals out. A wooden bin roughly 3 feet by 3 feet by 3 feet holds enough material to heat up and decompose fast. Plastic tumblers are smaller and faster but cost more and require you to turn them by hand.

If you live in an apartment or have no yard space, a small countertop bin or a bokashi bucket (which ferments rather than composts) works for food scraps. You can then bury the fermented material in a pot or community garden bed.

Key Takeaways

  • Layer brown materials (dry leaves, straw, shredded paper) with green materials (grass clippings, food scraps, plant trimmings) in roughly equal amounts by volume.
  • Keep the pile as moist as a wrung-out sponge and turn it every one to two weeks if you want finished compost in two to three months, or leave it undisturbed for six to twelve months.
  • Never add meat, dairy, oils, pet waste, or diseased plants, as these attract pests or introduce pathogens.
  • Finished compost looks dark brown, crumbly, and earthy and has no recognizable food scraps or plant pieces left in it.

Layer browns and greens in the right ratio

Brown materials are dry and carbon-rich: fallen leaves, straw, shredded newspaper, cardboard, wood chips, and sawdust. Green materials are wet and nitrogen-rich: grass clippings, vegetable scraps, coffee grounds, plant trimmings, and manure from herbivores like horses or chickens.

Aim for roughly equal volumes of each — a 1:1 ratio by eye works fine. Start with a layer of browns on the bottom (this helps air flow), then alternate: a few inches of greens, a few inches of browns, and so on. If your pile smells like ammonia or rotten eggs, you have too many greens; add more browns and turn it. If it is not heating up or breaking down, you have too many browns; add more greens or water.

Chop or shred materials before adding them — smaller pieces decompose faster. Whole leaves take months; shredded leaves take weeks. You can run a lawn mower over leaves in a pile or bag to shred them quickly.

Water and turn the pile to speed decomposition

Compost microorganisms need moisture to work. Keep the pile as moist as a wrung-out sponge — damp but not soggy. If it dries out, decomposition slows or stops. If it is waterlogged, it smells bad and rots instead of composting. Water it when the top feels dry, or after you add dry materials like leaves.

Turning the pile speeds decomposition by mixing materials, adding oxygen, and distributing moisture evenly. If you turn it every one to two weeks, you can have finished compost in two to three months. If you never turn it, decomposition takes six to twelve months but requires no work. Most home gardeners turn their piles every two to four weeks as a middle ground.

To turn a pile, move material from the outside edges (which are cooler and less decomposed) to the center, and material from the center to the outside. A pitchfork or garden fork works well. After turning, the pile heats up again as microorganisms resume rapid activity.

Know what not to add

Never add meat, fish, bones, dairy, oils, or fats — these attract rats, raccoons, and flies. Do not add pet waste (cat litter or dog feces), diseased plants, or weeds with seeds, as home compost piles do not get hot enough to kill pathogens or seeds. Avoid glossy or colored paper, which may contain chemicals.

Grass clippings are fine if they come from a lawn that has not been treated with herbicides or pesticides in the past few weeks. If you are unsure, leave them out. Sawdust and wood chips are safe only if they come from untreated wood — not pressure-treated lumber.

Citrus peels, onion skins, and garlic break down slowly and can repel worms, so use them sparingly. Bread, pasta, and grains attract pests and should go in a bokashi bucket or buried deep in the pile if you add them at all.

Recognize when compost is ready to use

Finished compost is dark brown or black, crumbly, and smells earthy — like forest soil. You should not see recognizable food scraps, leaves, or plant pieces. If you squeeze a handful, it holds together briefly but crumbles apart easily. It should feel cool, not hot.

The time to reach this stage depends on how often you turn the pile, how finely you chop materials, and how warm your climate is. A turned pile in warm weather can finish in six to eight weeks. An unturned pile in a cool climate may take a year or more.

You do not have to wait for the pile to be completely finished before using it. Partially decomposed compost still improves soil structure and adds nutrients. Spread it on garden beds in fall, and by spring it will have finished breaking down in the soil. If you want to use it when ready, screen out any large pieces and return them to the pile.

Troubleshoot common problems

Pile is not heating up: Add more green materials (grass, food scraps, manure) or water. The pile needs nitrogen and moisture to generate heat. Make sure it is at least 3 feet by 3 feet — smaller piles do not retain heat well.

Pile smells bad: This usually means too many greens or too much moisture. Turn the pile and add dry browns like leaves or shredded paper. Spread the pile out to let it dry slightly. Bad smell goes away within a few days of turning.

Flies or maggots in the pile: Cover food scraps with a layer of browns (leaves, straw, or soil) so they are not exposed. Do not add meat or dairy. If flies are already present, turn the pile — the heat will kill larvae.

Pile is soggy and not decomposing: Add browns and turn it to add air. Stop watering. If your area gets heavy rain, consider a cover or a bin with drainage holes.

Frequently Asked Questions

Can I compost in winter?

Yes, but decomposition slows dramatically in cold weather. A pile will not heat up or break down much below 40°F. In mild climates, you can keep adding materials and let the pile sit until spring. In very cold climates, many gardeners stop adding to the pile in fall and let it finish over winter and spring.

Do I need to add compost starter or microbes?

No. Soil, leaves, and finished compost already contain all the microorganisms you need. Adding a commercial starter does not speed decomposition noticeably. Save your money and use a shovel of finished compost or garden soil instead if you want to inoculate a new pile.

What if I do not have space for a big pile?

A smaller pile (2 feet by 2 feet) works but decomposes more slowly because it does not retain heat as well. A plastic tumbler or countertop bin is better for small spaces. You can also bury food scraps directly in garden beds or pots — they will decompose in place over a few weeks.

Can I compost diseased plant material?

Home compost piles do not reach the sustained high temperatures needed to kill most plant diseases. Leave out plants with powdery mildew, blight, or root rot. Healthy plant trimmings are fine.

How do I keep rodents out of my compost?

Use a bin with a lid and a solid bottom, or a tumbler. Avoid meat, dairy, and oils. Bury food scraps under at least 6 inches of browns. If rodents are already present, stop adding food scraps temporarily and turn the pile frequently — the activity and heat discourage them.