Compost Tumbler Not Heating Up? Winter Warm-Up Trick

The Cold-Weather Slowdown

Composting microbes go dormant in freezing temps. Your tumbler's ¾ full but stalled because fungi and bacteria have stopped working.

Simple Solar Solution

Cover the tumbler completely with clear plastic sheeting extending to the ground on all sides. This creates a mini-greenhouse that traps solar heat and jump-starts microbial activity.

Why It Works

• Clear plastic transmits sunlight but traps infrared heat.
• Even weak winter sun raises internal temps 20–30°F.
• Microbes reactivate, decomposition resumes.

Additional Tips

• Ensure contents are moist (like a wrung sponge).
• Keep turning 2×/week for aeration.
• Balance greens (nitrogen) and browns (carbon).