Why Some Compost Chunks Dont Break Down

#permaculture #composting #organicgardening
Joanna asked a great question: how finely should you chop your carbon materials, and why do some pieces in compost piles take so long to break down? In this Q&A, Geoff walks us through real compost piles, showing the process from fresh brown and green materials to rich, life-filled soil. He explains why some stubborn chunks and matted roots remain, how climate affects decomposition, and why the true value of compost isn’t just texture—it’s the billions of microorganisms it brings to your garden.

Geoff’s Online Permaculture Design Course includes weekly video Q&A sessions where he answers student questions. This one comes from the 2019 archive. Learn more about Geoff’s online courses at https://www.discoverpermaculture.com.

Key Takeaways:

Large chunks and woody material take longer to break down; climate, moisture, and heat affect decomposition rates.
Even compost with small unbroken pieces is full of life and nutrients—it’s a living ecosystem, not just a soil amendment.
Frequent turning (e.g., 3x per week) and maintaining moisture helps accelerate decomposition in medium-sized piles.
In cold climates, composting may require protection like a glasshouse or plastic cover to maintain heat and microbial activity.
For fine-seeded plants, compost can be sieved to create a smooth potting mix, but larger particles are fine for general soil improvement.
True compost is colloidal, with particles under 15 microns and millions of microorganisms, making it a “living inoculum” for your garden.