Yes, you should cover your compost pile—but the reason depends on what problem you're trying to solve

A cover is not required for compost to break down, but it solves three real problems: it keeps rain from waterlogging the pile, it stops rodents and raccoons from digging through your scraps, and it slows moisture loss on hot days. If you live where it rains heavily, have a pest problem, or want faster decomposition, a cover pays for itself. If your pile sits in shade, you water it regularly, and you don't have wildlife nearby, you can skip it.

The best covers are breathable—wood pallets, burlap, or a tarp with gaps—because compost needs air to decompose properly. A sealed plastic tarp will suffocate your pile and create odor instead of solving problems. The material you choose matters as much as whether you cover at all.

Key Takeaways

  • A cover prevents rain from turning your pile into a soggy, anaerobic mess that smells like rotten eggs instead of earth.
  • Solid covers like tarps or plywood stop rodents and raccoons from nesting in your pile and scattering food scraps across your yard.
  • Breathable covers made from wood pallets or burlap work better than solid plastic because compost needs oxygen to decompose efficiently.
  • In wet climates or during rainy seasons, a cover is nearly essential; in dry climates, it can actually slow decomposition by blocking moisture.
  • A cover also speeds up decomposition by keeping the pile's internal temperature stable and preventing heat loss at night.

Why moisture control is the main reason to cover

Compost needs moisture—roughly the wetness of a wrung-out sponge—but too much water creates an oxygen-starved environment where anaerobic bacteria take over. When that happens, your pile smells like sulfur or rotten eggs instead of soil, and decomposition slows to a crawl. A cover prevents rain from adding water faster than the pile can drain and use it.

In areas with regular rainfall or during wet seasons, a cover is the difference between a working pile and a waterlogged brick. Even in drier climates, a cover helps during heavy storms. The key is choosing one that lets air through: a solid tarp sealed at the edges will trap moisture and create the exact problem you're trying to prevent. Instead, use a tarp with gaps, a wooden pallet frame, or burlap that allows rain to filter through slowly while blocking the heaviest downpours.

How a cover stops rodents and other pests

Rats, mice, and raccoons are attracted to compost because it contains food scraps—especially meat, dairy, and oils if you're composting those. A cover doesn't eliminate the smell, but it makes the pile harder to access. Rodents can chew through plastic, so a solid tarp alone won't stop them; you need weight on top (bricks, boards, or soil) to make entry difficult enough that they move on to easier food sources.

A wooden pallet cover weighted down with concrete blocks is one of the most effective barriers because it's heavy, rigid, and lets air flow underneath. Hardware cloth (a metal mesh) buried around the base of the pile stops burrowing animals from tunneling underneath. If you live in an area with a serious rodent or raccoon problem, combining a weighted cover with buried mesh is your best defense. Without a cover, you're essentially running a buffet.

The difference between solid and breathable covers

A solid plastic tarp or sheet of plywood creates problems if it seals the pile completely. Compost is an aerobic process—it requires oxygen—and a sealed cover cuts off airflow, slowing decomposition and creating odor. Solid covers also trap moisture underneath, turning your pile into a swamp. Use a solid cover only as a temporary measure during extreme weather, and lift it or poke holes in it within a few days.

Breathable covers work much better. A wooden pallet laid flat on top of the pile lets air circulate while blocking rain and pests. Burlap or landscape fabric pinned down achieves the same effect. You can also build a straightforward frame from scrap wood and cover it with burlap or old netting. These materials slow rain penetration without suffocating the pile, and they're cheap or free if you salvage pallets or old fabric from around your house.

Timing: when to cover and when to leave it open

Cover your pile during rainy seasons or if heavy rain is forecast. In dry climates, a cover can actually slow decomposition by blocking moisture that would otherwise soak in from morning dew or occasional rain. If you're in a dry area and your pile is drying out too fast (the center is hot but the edges are dry and crumbly), a cover helps retain moisture. If you're in a wet area and your pile smells bad or feels soggy, a cover is urgent.

During active composting—when you're regularly adding scraps and the pile is heating up—a cover helps trap that heat and speeds the process. Once your pile is finished and you're letting it cure, you can leave it uncovered or covered depending on weather. If you're storing finished compost outdoors for months, a cover keeps it from washing away in rain and prevents new weeds from seeding into it.

Building a straightforward cover from materials you have

You don't need to buy a commercial compost cover. A wooden pallet is the easiest option: lay it flat on top of your pile and weight it down with bricks or concrete blocks at the corners. If the pallet is rotting, it will eventually become part of your compost, which is fine. For a more permanent solution, build a straightforward frame from 2x4s the size of your pile's top, then staple burlap or old landscape fabric to it. This frame can be lifted off to turn the pile or add scraps.

Old tarps work if you weight them down heavily and poke holes or leave gaps around the edges for air. Avoid sealing the tarp completely—drill holes or fold back one corner to let moisture and gases escape. Some people use old shower curtains, vinyl tablecloths, or even cardboard weighted with soil, though these break down faster and need replacing. The goal is something that blocks rain and pests but doesn't suffocate the pile.

Signs your pile needs a cover right now

If your compost smells like rotten eggs or ammonia, it's too wet and needs a cover when ready to stop rain from adding more water. If you see rodent droppings, chewed food scraps scattered around the pile, or holes dug into it, a weighted cover is essential. If you live in a region with heavy spring or fall rains and your pile has turned into a muddy, compacted mass, a cover will prevent that next season.

If your pile is in full sun and drying out so fast that the edges are crispy and the center isn't heating up, a breathable cover will help retain moisture and speed decomposition. If you're composting in an urban area where neighbors are nearby, a cover reduces smell and keeps the pile looking intentional rather than like a trash heap, which matters for keeping the peace.

Frequently Asked Questions

Can I use a solid plastic tarp as a permanent cover?

No. A sealed plastic tarp will suffocate your pile by blocking oxygen and trapping moisture, creating odor and slowing decomposition. Use plastic only during heavy rain or snow, and remove it or poke holes in it within a few days. For permanent coverage, choose burlap, landscape fabric, wood pallets, or netting.

Will a cover prevent my compost from getting enough water?

A breathable cover will not prevent water from reaching your pile—rain filters through burlap and fabric, and air gaps let moisture in. A solid tarp will block water, which is a problem in dry climates. In wet climates, blocking some rain is the whole point. Choose your cover based on your climate: breathable in wet areas, or no cover in dry areas unless your pile is drying out too fast.

Do I need to cover a compost bin instead of a pile?

Most compost bins come with a lid, which serves the same purpose as a cover. If your bin doesn't have a lid, adding one (even a straightforward wooden frame with burlap) will help control moisture and keep pests out. Bins with solid plastic lids should have ventilation holes or gaps to let air flow through.

What's the best material for a compost cover?

Wooden pallets are the easiest and cheapest option—they're often free, they let air through, and they're heavy enough to stay in place. Burlap or landscape fabric stapled to a wood frame is more durable. Avoid solid plastic, and don't use treated wood that contains chemicals. Whatever you choose, make sure it's weighted down so wind and animals can't move it.

Can I compost without a cover at all?

Yes, if you live in a dry climate, your pile is in shade, you water it regularly, and you don't have a rodent or raccoon problem. Many gardeners compost uncovered without issues. A cover becomes necessary when rain is heavy, pests are a problem, or you want faster decomposition. Start without one and add a cover only if you run into problems.