You can build a working composter from materials you likely have or can buy cheaply
A homemade composter does the same job as a store-bought one: it holds kitchen scraps and yard waste in a contained space where they break down into usable compost. The simplest designs use a plastic bin with holes drilled in it, a wooden box built from untreated lumber, or a wire cylinder made from fencing. None of these require special tools, and most cost between $20 and $60 to build. The design you choose depends on how much space you have, how often you want to turn the pile, and whether you prefer something you can access from the side or the bottom.
Each design works because it does three things: it holds material in one place, it lets air reach the decomposing pile, and it lets excess water drain out. The speed at which your compost finishes depends more on how often you turn it and how small you chop the scraps than on which design you pick. A bin you turn weekly will finish in two to three months; a pile you leave alone will take four to six months or longer.
Key Takeaways
- A plastic bin composter is the fastest to build and works well in small spaces, but you will need to turn the contents by hand every week or two.
- A wooden box composter is larger and easier to turn if you build it with removable front slats, and untreated wood lasts three to five years before rotting.
- A wire cylinder composter takes up minimal space and is straightforward to build, but works best if you turn it frequently and have room to lift it off the pile.
- All three designs need drainage holes or gaps to let air reach the decomposing material, and all work faster if you chop scraps into smaller pieces before adding them.
- The location matters as much as the design—place your composter in partial shade, away from wooden structures, and where water can drain away from your foundation.
The plastic bin composter: fastest to build and best for apartments
A plastic storage bin with a tight-fitting lid becomes a working composter in about 30 minutes. Buy a 20- to 30-gallon opaque plastic bin (dark color helps retain heat), a power drill with a quarter-inch bit, and a small hinge and latch if you want to make the lid removable. Drill holes in the bottom, sides, and lid—space them about 4 inches apart in a grid pattern. The bottom holes let liquid drain out; the side holes let air in; the lid holes prevent the pile from becoming waterlogged.
Place the bin on a pallet or concrete blocks so air can flow underneath. Add a layer of coarse material like twigs or shredded paper at the bottom to keep the pile from compacting. Then alternate layers of "brown" material (dry leaves, shredded paper, cardboard) and "green" material (food scraps, grass clippings, coffee grounds) in roughly equal amounts by volume. Once a week, close the lid and shake or roll the bin to turn the contents. This design works in a garage, basement, or apartment balcony because it is contained and odor-free if you maintain the brown-to-green ratio.
The wooden box composter: larger capacity and easier access
A wooden composter built from untreated lumber gives you more room to work with and lets you pull finished compost from the bottom without disturbing the pile above. You will need eight 8-foot boards (2 inches by 10 inches), a power drill, 3-inch wood screws, and a saw. Cut four boards to 3 feet long for the front and back, and leave four at 4 feet for the sides. Assemble them into a box by drilling pilot holes and driving screws through the sides into the ends of the front and back boards. Leave a 1-inch gap between each board to allow air flow, or drill 1-inch holes in a grid pattern if you prefer a tighter fit.
Build the front with removable slats instead of a solid panel—attach the top slat with hinges and let the lower slats rest loosely in slots cut into the side boards. This lets you pull out slats from the bottom as the pile settles and remove finished compost without opening the whole box. Place the composter on bare soil so worms and microorganisms can move in from below. Fill it the same way as a bin: coarse material first, then alternating brown and green layers. Turn the pile every two to three weeks by moving material from one side to another, or straightforward wait longer (four to six months) and let it decompose without turning.
The wire cylinder composter: minimal footprint and quick assembly
A cylinder made from wire fencing is the easiest design to build and takes up the least space. Buy 12 feet of 1/2-inch hardware cloth or chicken wire (16-gauge or thicker), wire cutters, and heavy-duty wire or zip ties. Roll the fencing into a cylinder about 3 feet in diameter and 3 feet tall, and find the overlapping edges with wire or zip ties every 6 inches. Stand it upright on bare soil in your yard.
Fill the cylinder the same way as other designs: brown and green layers, starting with coarse material at the bottom. The open sides let air reach the pile from all directions, which speeds decomposition. Every two to three weeks, lift the entire cylinder straight up and set it down next to the pile you just made. Use a pitchfork to move the partially decomposed material back into the cylinder, which turns it and exposes new material to air and moisture. This design works best if you have the space to move it around and the strength to lift it when it is full. It also works well in a vegetable garden because you can move it to a new spot each season.
Location, drainage, and what to put in your composter
Where you place your composter matters as much as how you build it. Choose a spot that gets partial shade—full sun dries out the pile too fast, and full shade slows decomposition. Make sure water drains away from the site so the pile does not become waterlogged. Keep the composter at least 3 feet away from wooden fences, sheds, or your house, because the moisture and decomposition can damage wood over time. If you live in a cold climate, place it in a sunny spot to help the pile stay warm enough to break down material.
Add roughly equal volumes of brown material (dry leaves, shredded paper, cardboard, straw, wood chips) and green material (food scraps, grass clippings, plant trimmings, coffee grounds, tea bags). Chop or shred everything into pieces smaller than 2 inches—smaller pieces decompose faster. Avoid meat, fish, dairy, oils, and pet waste, which attract pests or introduce harmful bacteria. If you add grass clippings, mix them with brown material so they do not mat down and block air flow. Keep the pile as moist as a wrung-out sponge; if it smells like ammonia, add more brown material and turn it more often.
How long it takes and when your compost is ready
The time from start to finished compost depends on how often you turn the pile and how small you chop the material. A bin or wooden box that you turn every week or two can produce usable compost in two to three months. A wire cylinder turned frequently may be ready in three to four months. If you do not turn the pile at all, expect four to six months in warm weather, or longer in cold climates. Finished compost looks like dark, crumbly soil, smells earthy, and falls apart in your hand.
You do not have to wait until everything is completely finished before using it. Pull out the dark material from the bottom of a wooden box or bin and use it in garden beds or potted plants. The material still breaking down at the top can stay in the composter and continue decomposing. This way you get a continuous supply of compost without having to empty the whole bin at once.
Maintaining your homemade composter through the seasons
In warm months, your composter will work fastest because microorganisms are most active. Keep adding scraps and turning the pile regularly. In fall, add shredded leaves—this is when most people have the most brown material available. In winter, decomposition slows dramatically in cold climates, but you can still add scraps; they will break down when the weather warms. In spring, the pile usually heats up again and finishes breaking down the winter additions.
Wooden composters last three to five years before the wood begins to rot, especially at the bottom where it sits on damp soil. You can extend the life by replacing rotted boards or by building a new one when the old one fails. Plastic bins last longer but can become brittle in direct sunlight after several years. Wire cylinders last indefinitely but may rust if you use uncoated steel; galvanized or stainless steel wire lasts much longer.
Frequently Asked Questions
Do I need a lid on my composter?
A lid helps keep rain from waterlogging the pile and prevents animals from digging in, but it is not required. A plastic bin or wooden box with a lid decomposes slightly faster because it retains heat better. A wire cylinder works fine without a lid, though you may want to cover it during heavy rain.
What if my composter smells bad?
A rotten or ammonia smell means the pile is too wet or has too much green material. Add shredded paper, dry leaves, or cardboard to balance it out, and turn the pile to let air in. A properly balanced composter should smell earthy, not foul.
Can I use treated wood to build a composter?
No. Treated wood contains chemicals that can leach into your compost and soil. Use untreated lumber, or build with plastic or wire instead. Cedar and redwood are naturally rot-resistant and safe, but they cost more than standard untreated boards.
How do I keep rodents out of my composter?
Avoid adding meat, fish, dairy, or oils, which attract rats and mice. Use a bin or wooden box with a tight-fitting lid rather than an open wire cylinder. If rodents are a problem in your area, bury food scraps under at least 8 inches of brown material so they are not visible from the surface.
Can I compost diseased plants or weeds with seeds?
Only if your pile gets hot enough to kill the pathogens and seeds. A well-maintained pile that you turn frequently reaches 130 to 150 degrees Fahrenheit, which kills most weed seeds and plant diseases. If you are not sure your pile is hot enough, leave out diseased plants and weeds with mature seeds.