Composting in Canada: 7 Easy Steps to Compost Year-Round (Even in Winter)

Quick answer: Composting in Canada works year-round. Mix about 2–3 parts "browns" (dry leaves, cardboard) with 1 part "greens" (food scraps, grass), keep the pile as damp as a wrung-out sponge, and turn it every week or two. In winter the pile freezes and pauses, but you can keep adding scraps. It all breaks down quickly once the pile thaws in spring.

Key takeaways

• Save bags of fall leaves now. They're the brown material you'll need all year.
• A frozen compost pile isn't a failed pile. Composting in Canada simply pauses in winter and picks up again in April.
• Most smells come from too many greens or too much water. Fix them by adding browns.
• Your city green bin takes things a backyard pile can't, like meat, bones and dairy.

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Why composting in Canada is worth it

Compost improves any garden soil. It loosens heavy Ontario clay, helps sandy soil hold water, and feeds the soil life that feeds your plants. Composting in Canada also keeps food waste out of landfill and saves you buying bags of soil every spring.

Greens and browns: the basic recipe

Greens (nitrogen)	Browns (carbon)
Fruit and vegetable scraps	Dry leaves
Coffee grounds and tea leaves	Shredded cardboard and paper
Fresh grass clippings	Straw
Garden trimmings (not diseased)	Wood chips (small amounts)
Plant-based kitchen waste	Paper egg cartons

Ratio: about 2–3 parts browns to 1 part greens, by volume. You don't need to be exact. If the pile is wet and smelly, add browns. If it's dry and doing nothing, add greens and water.

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What NOT to put in a backyard composter

• Meat, fish, bones and dairy (they attract raccoons, rats and smells)
• Oils and greasy food
• Pet waste
• Diseased plants and weeds that have gone to seed
• Walnut leaves and hulls in large amounts (black walnut can harm some plants)

Many of these can go in your municipal green bin instead. Toronto, Peel, Halton and many other Ontario municipalities collect them, because industrial composting runs hot enough to break them down safely. Check your city's list.

Composting in Canada: 7 easy steps

1. Pick a spot that's level and well drained, partly sunny, and close enough to the house that you'll use it in winter.
2. Choose a bin. An enclosed plastic composter works well in towns and cities because it keeps animals out. Many Ontario municipalities sell them at a discount, so check before you buy.
3. Start with browns. Put 10–15 cm of twigs or coarse leaves on the bottom for airflow.
4. Layer greens and browns as you add material. Always cover fresh food scraps with browns.
5. Keep it damp, like a wrung-out sponge.
6. Turn or poke it every week or two to add air.
7. Harvest the dark, crumbly compost from the bottom when it's ready.

For a printable cold-climate version, the City of Yellowknife's Guide to Backyard Compost is excellent. If it works in Yellowknife, it works in Ontario.

Composting in Canada through the winter

This is the part Canadians always ask about. Here's what actually happens:

• Late fall: Stockpile bagged leaves next to the bin. You'll need them as browns all winter.
• December to March: The pile freezes. Keep adding kitchen scraps on top and cover each addition with a handful of leaves. Freezing actually helps break down cell walls.
• Insulation (optional): Packing leaves or straw bales around the bin keeps the core active longer into the cold season.
• Spring thaw: The pile may be wet and soggy at first. Mix in plenty of dry browns, turn it, and it will heat up quickly.

Tip: Keep a lidded pail with a charcoal filter under the sink, or a larger bucket by the back door, so you don't have to trek through snow every day.

How long until compost is ready?

A well-managed pile in an Ontario summer can be ready in 2–4 months. A pile you mostly leave alone takes 6–12 months. Finished compost is dark and crumbly and smells like a forest floor. You shouldn't be able to recognize any of the original scraps.

Fixing common compost problems

Problem	Likely cause	Fix
Rotten-egg or ammonia smell	Too wet, or too many greens	Add browns and turn the pile
Pile not heating up	Too dry, too small, or too many browns	Add greens and water, and build it bigger
Fruit flies	Exposed food	Bury scraps and cover them with browns
Animals digging	Meat or dairy, or an open bin	Remove those items and use an enclosed bin
Slimy grass layer	Thick layer of fresh clippings	Mix clippings with leaves

Using your compost

• Spread 2–5 cm on vegetable beds every spring.
• Mix it into planting holes for trees and shrubs.
• Top-dress your lawn with a thin layer in fall.
• Blend it into potting mix (no more than about a quarter compost).

The Compost Council of Canada's directions for use give more detail on how much to apply. Using compost every year is the simplest way to improve your soil, especially before planting garlic. See when to plant garlic in Ontario.

FAQ: composting in Canada

Can you compost in winter in Canada?

Yes. The pile freezes and stops breaking down, but you can keep adding scraps all winter. Composting in Canada picks up again quickly once the pile thaws in spring.

Should I use the green bin or a backyard composter?

Both. Use the backyard composter for fruit, vegetable and yard waste, and use the green bin for meat, bones, dairy and other things a home pile can't handle.

Do I need to turn my compost?

No, but it helps. Turning adds oxygen and speeds things up. A pile you never turn still makes compost, just more slowly.

Can I compost fall leaves on their own?

Yes, they make leaf mould, a great soil conditioner, in 1–2 years. Shredding them with a lawn mower speeds things up.

Doing your fall cleanup? Our Ontario fall garden checklist includes what to do with your leaves.