How to Make Hot Compost
By Sami Grover
Many people worry too much about compost - after all, leave anything biodegradable long enough, and it'll pretty much turn into compost. As long as there is some air, and a reasonable mix of different materials, compost will happen.
Nevertheless - there is something deeply satisfying about building a proper hot compost heap and watching it steam on a cold morning. Not only does it rot faster than a slow heap - but it can also help eliminate perennial weeds and/or diseases that might be spread to other plants or beds. And these things do get hot - in fact, you shouldn't be able to hold your arm inside a truly hot heap for more than 20 seconds without it getting very uncomfortable.
Jasmin has already covered a few tips for making hot compost fast, and our composting quiz should help you differentiate what can and can't be added to your pile. But as someone who has finally found the space and time to get a truly steaming pile going in his yard, I thought I'd share a few hints:
- Think big: You need to create a heap at least four or five feet across and a four or five feet high.
- Mix it up: You need to mix woody, carbon rich waste with softer, nitrogen rich waste. Somewhere around 20 to 25 parts carbon to one part nitrogen is the correct ratio - but there is no need to be too exact. Just remember you need more browns (carbon) like leaves, hay, straw, and woody plant material, and less greens (nitrogen) like coffee grounds, lawn clippings, kitchen waste etc.
- Think fast: Build the heap over a matter of weeks, not months -that way you are not 'diluting' the heap by adding bulky materials that need to start decomposing when everything else is already rotting like crazy.
- Water well: Spray the heap with a hose from time to time. Peeing on your heap can also help - with the added benefit that you'll be providing vital nutrients.
- Insulate: Lining the sides and top of your heap with cardboard can help keep temperatures up.
- Turn it over: The bacteria and micro-fauna that are busy breaking down your waste need oxygen - so turning the heap every few weeks helps keep them alive, ensures an even rate of decomposition, and it also lets you check that the heap is not getting too hot or too dry. (If you see ash-like substance forming, it's probably too hot - just keep turning it and watering it and it'll settle down.)
And that's about it. Play your cards right and you could be harvesting fresh, free and abundant compost within a matter of a few months. And if this all seems like too much trouble, you can build your own DIY compost tumbler.
Need proof that it's possible to balance being green and still be a supportive partner and parent? See how Ed Begley, Jr. does it on Planet Green TV's Living with Ed.