Heating Up a Nearly Finished Compost Heap

by Anita Malherbe
(Limpopo RSA)

My compost heap is about 80% decomposed. I made it in the normal way and it didn't get warm during the composting process.

There are still unwanted seeds and pathogens in the heap. How can I heat that heap up again so that I can kill all those seeds and pathogens?

Heat, Seeds, and Pathogens

Hi Anita

Thank you for your question. It's so interesting that your compost is 80% decomposed despite not heating up. Seems we are all looking for a super hot compost. The story goes that heat is what deals a death blow to seeds and pathogens.

Heat does do that. But what also does the job is the biodiversity of microbes in your compost heap and time.

A very hot compost works fast but a cooler slower compost also does the job. It just does it more slowly. And as a bonus you tend to get a finished compost that has more biodiversity in it. This community of microbes are up to the task of keeping pathogens under control. Maybe your compost is pretty much ready.

However, I notice you are in South Africa. I've heard that parts of RSA are suffering severe drought. I'm wondering whether you are coping with water shortages at the moment. The reason I ask is I live in a very dry area. In our area 9 times out of 10 the reason compost stops breaking down is because it's too dry. Could this be a factor for you.

If you squeeze a handful of the compost you should get a drop or two of water come out. If not it's probably too dry. The fix is to turn your pile wetting it as you go. You can use any water you can get a hold of. This would pretty quickly get the pile heating up again.

Hope this is helpful

Cheers
Leslie