Start with a bin, brown materials, and green materials

Making compost is a straightforward layering process: you build a pile or use a bin, alternate dry brown materials (leaves, shredded paper, cardboard) with wet green materials (food scraps, grass clippings, plant trimmings), keep it moist like a wrung-out sponge, turn it occasionally, and in two to six months you have dark, crumbly finished compost. You do not need special equipment, special microbes, or special knowledge—the bacteria and fungi already in your yard do the work.

The speed depends on how often you turn the pile, how finely you chop the materials, and the season. A pile you turn weekly can finish in two months. A pile you leave alone can take six months to a year. Both produce the same end product.

Key Takeaways

  • Layer brown materials (dry leaves, shredded paper, cardboard) with green materials (food scraps, grass clippings) in roughly equal amounts by volume.
  • Keep the pile as moist as a wrung-out sponge—too dry and decomposition stalls, too wet and it smells.
  • Turn the pile every week or two if you want finished compost in two months, or leave it alone for six months to a year.
  • You can use a purchased bin, a wooden frame you build yourself, or straightforward a pile on the ground with no structure at all.
  • Finished compost is dark brown, crumbly, and smells earthy—not like the food scraps you put in.

What materials go in and what does not

Green materials (nitrogen-rich, wet) include fruit and vegetable scraps, coffee grounds and tea bags, fresh grass clippings, plant trimmings, and manure from herbivores like horses, rabbits, or chickens. Brown materials (carbon-rich, dry) include fallen leaves, shredded newspaper and cardboard, straw, wood chips, and sawdust.

Do not add meat, fish, dairy, oils, or fats—they attract rats and create odor. Do not add pet feces, diseased plants, or weeds that have gone to seed. Do not add glossy or colored paper, pressure-treated wood, or charcoal ash. Plain wood ash from a fireplace is fine in small amounts.

Grass clippings are green material, but if your lawn was treated with herbicide or pesticide, let the clippings dry for a few weeks before adding them. Diseased plant material should go in the trash, not the compost, because home piles do not get hot enough to kill all pathogens.

Building and layering your pile or bin

If you are using a bin, start with a layer of brown material about 4 inches deep on the bottom—this lets air flow underneath. Then add a layer of green material about 4 inches deep. Alternate brown and green until the bin is full or you run out of material. Aim for roughly equal volumes of brown and green, though the exact ratio is not critical.

If you are building a pile on the ground with no bin, the same layering works. Start on bare soil so worms and microbes can move in from below. Make the pile at least 3 feet wide and 3 feet tall—smaller piles do not heat up as much and decompose more slowly.

Chop or shred materials before adding them if you can. Smaller pieces decompose faster because microbes have more surface area to work on. A pile of whole leaves takes longer than a pile of shredded leaves.

Moisture and aeration—the two things that matter most

The pile should feel like a wrung-out sponge: moist throughout, but not dripping. If it is too dry, decomposition slows or stops. If it is too wet, it becomes anaerobic (oxygen-starved), and you get a sour smell like vinegar or rotten eggs.

Water the pile when you add new material if the existing pile feels dry. After rain, check the center of the pile—the outside may be wet while the inside is still dry. If the pile smells bad, it is too wet; add dry brown material and turn it to introduce air.

Turning the pile means moving material from the outside to the center, where decomposition is fastest. A pile turned once a week finishes in about two months. A pile turned every two to three weeks takes three to four months. A pile you never turn takes six months to a year. Turning is optional—it just speeds things up.

How to know when compost is finished

Finished compost is dark brown or black, crumbly, and smells earthy—like soil after rain. You should not be able to recognize the food scraps or leaves you put in. If you can still see chunks of material, it is not ready yet.

A straightforward test: fill a clear jar halfway with the material from the center of your pile, add water, seal it, and shake it hard. Let it sit for a day. If the material settles into distinct layers (sand at the bottom, silt in the middle, clay on top), decomposition is still happening. If it stays mixed and muddy, it is close to finished.

You can use partially finished compost in garden beds—it will continue to break down in the soil. But for potting mix or for spreading on top of beds where you want a neat appearance, wait until it is fully dark and crumbly.

Bin options: purchased, built, or no bin at all

A purchased plastic bin costs $50 to $150, takes up about 3 feet by 3 feet of space, and usually has a door at the bottom so you can pull out finished compost without dismantling the whole pile. Brands like Rubbermaid and Suncast are common at garden centers. The downside is that plastic bins can be slow to decompose material because they do not let air flow as freely as an open pile.

A wooden frame you build yourself costs $20 to $40 in materials (untreated wood, wire, or metal brackets) and takes a weekend to assemble. A straightforward design is four wooden pallets wired together to make a square. Wooden bins decompose faster than plastic because air flows through the gaps, but the wood itself rots over time and needs replacing every few years.

A pile with no bin costs nothing and works just as well. You can mark the edges with stakes or rope if you want to keep it tidy. The downside is that it takes up more visible space and rodents can burrow in from the sides more easily. If you have a rat problem in your area, a bin with a solid bottom and a door is a better choice.

Troubleshooting common problems

If the pile smells like ammonia or rotten eggs, it is too wet or has too much green material. Add dry brown material (leaves, shredded paper, cardboard) and turn the pile to introduce air. If it smells like vinegar, it is anaerobic—turn it when ready and add brown material.

If the pile is not heating up or decomposing, it is probably too dry or too small. Water it and add more material. A pile smaller than 3 feet by 3 feet by 3 feet does not generate enough heat to decompose quickly. If you have very little material, you can wait until you have more before starting.

If you see rats or mice, you added meat, fish, dairy, or oils. Remove those materials if you can find them, and do not add them again. A bin with a solid bottom and a locking door is your best defense. If rodents are already established, you may need to dismantle the pile, remove the rodents, and start over in a new location or in a closed bin.

If flies are swarming, bury food scraps under at least 6 inches of brown material so they are not exposed. Flies lay eggs on the surface of exposed food. A layer of leaves or shredded paper on top of each layer of green material stops most fly problems.

Frequently Asked Questions

Can I compost in winter?

Yes, but decomposition slows dramatically in cold weather. A pile you start in fall will not finish until spring or early summer. If you want to keep composting year-round in a cold climate, an insulated bin or a pile in a sheltered spot (against a south-facing wall, for example) decomposes faster. In mild climates, composting continues through winter at a normal pace.

Do I need to add compost starter or special microbes?

No. The bacteria and fungi that decompose organic matter are already in your yard, in the soil, and on the materials you add. Commercial compost starters are not necessary. If you want to speed decomposition slightly, you can add a shovel of finished compost or garden soil to a new pile, but this is optional.

What if I do not have brown materials?

Shredded newspaper, cardboard, or straw work well. You can also let grass clippings dry in the sun for a few days before adding them—they become brown material. If you truly have no brown materials available, decomposition will be slower and the pile may smell, but it will still work if you keep it from getting waterlogged.

Can I compost sawdust or wood chips?

Yes, but use untreated wood only. Sawdust from pressure-treated lumber or plywood contains chemicals that should not go in compost. Untreated sawdust and wood chips are excellent brown materials and decompose over time. Mix them with green material so the pile does not become too carbon-heavy.

How much finished compost will I get?

A pile shrinks as it decomposes—roughly to one-third its original volume. A 3-foot by 3-foot by 3-foot pile (27 cubic feet) will yield about 9 cubic feet of finished compost. The exact amount depends on what materials you used and how long you let it decompose.