Winter Composting: Keep Your Heap Active
Composting doesn’t need to stop when temperatures drop. With the right setup, you can keep your heap active through winter in the UK, USA, Canada, Australia and New Zealand. Winter composting is slower, but it’s absolutely possible—and a well-managed cold-season heap gives you a strong spring head start.
Why Composting Slows Down in Winter
Microbial activity drops as temperatures fall. Worms retreat deeper into the pile, moisture levels change, and heaps compact more easily. The trick is maintaining a balance of insulation, airflow and moisture so the biology can keep ticking along.
How to Prepare Your Compost for Winter
- Build a larger pile: Bigger heaps hold heat better.
- Add insulation: Straw, leaves, old carpet or cardboard.
- Turn the heap before the cold hits: Improve oxygen flow.
- Stockpile browns: Leaves and cardboard for winter balancing.
Feeding Your Compost Through Winter
Food scraps continue to break down, just more slowly. Keep adding them, but balance with dry carbon-rich materials to avoid soggy clumps.
- Chop scraps smaller for faster breakdown.
- Add leaves or shredded cardboard with every food layer.
- Avoid large amounts of citrus in cold months.
Hot Bins vs Cold Heaps in Winter
Hot Bins
Insulated systems like HotBins or similar brands stay active even below freezing. They can digest cooked food and small amounts of dairy year-round.
Cold Heaps
These slow down heavily, but don’t stop entirely. Expect composting to continue at 20–30 percent of summer rate.
Winter Composting by Region
- UK & Ireland: Wet winters mean moisture control is crucial.
- USA: Northern states need insulation; southern states compost year-round.
- Canada: Deep freezes slow heaps almost fully; pre-winter prep is essential.
- Australia: Winter is mild; great time for building compost.
- New Zealand: Ideal temperatures for consistent winter composting.
Common Winter Compost Problems
1. Frozen Layers
Normal in harsh climates. Keep feeding; the pile will restart in spring.
2. Bad Smells
Add more browns, turn lightly, and cover with leaves.
3. Pest Activity
Use lids, wire mesh and avoid proteins.
Advanced Tricks to Keep the Pile Warm
- Layer in fresh manure for heat.
- Add a compost duvet (thick brown layer).
- Keep the heap sheltered from wind.
- Use a vented compost cover.
FAQs
Should I stop adding food in winter? No—just balance with browns.
Do worms survive freezing? Yes, they retreat deeper where temperatures stay stable.
Will a frozen pile restart? Absolutely—as soon as temperatures rise.
Related: Hot Composting Guide · What Not to Compost · Compost Accelerators · Compost Systems Compared
