01Add as you go

Unlike a hot pile built all at once, a cold compost heap is simply added to gradually over time — much less effort, at the cost of a slower breakdown and a pile that doesn't get hot enough to kill weed seeds reliably.

02What you'll need

A bin, bay, or simple heap area
A steady supply of kitchen and garden scraps
Occasional dry material (leaves, straw, shredded paper) to balance wet scraps

03Method

1. Choose a bin or a simple contained heap in a convenient spot.
2. Add kitchen scraps and garden waste as they're generated.
3. Mix in dry brown material occasionally to avoid a slimy, anaerobic pile.
4. Turn occasionally if convenient, though it isn't essential.
5. Let the base of the pile mature undisturbed; harvest finished compost from the bottom while continuing to add to the top.

04Troubleshooting

Slimy, smelly pile — too much wet green material; add dry browns and improve drainage.
Very slow breakdown — normal for cold composting; be patient, or switch to hot composting if speed matters.
Weed seeds surviving — cold piles don't reliably kill weed seeds; avoid adding seeding weeds if this is a concern.
Pests — avoid meat and dairy scraps; bury fresh additions under existing material.

05Timing & maintenance

Best time

Can be started any time; an ongoing, ever-present system rather than a seasonal task.

Duration

6–12 months for material added early in the pile's life to fully break down.

Maintenance

Minimal — add material as available, turn occasionally if convenient.

Signs of success

The bottom of the pile becomes dark, crumbly, and earthy while the top is still recognisable scraps.

06Tips & variations

Pairs well with

MulchingBuilding Healthy Soil

Common mistakes

Adding too much wet material without balancing brownsExpecting hot-pile speed from a cold system

Pro tip

A two- or three-bay system lets one bay mature undisturbed while you keep adding to another.

Cold & Slow Composting