Mature compost is the best fertilizer for the garden – and a natural and free one at that. But in order for organic waste to turn into beneficial substrate, the compost heap in your garden should be open at the bottom.
Only then can earthworms and other invertebrates get in and aid the rotting process. Germany’s Agency for Renewable Resources (FNR) therefore advises against using containers that are closed at the bottom or covering the soil with stone slabs. A location in partial shade is also a good idea.
The right mixture
The agency recommends shredding larger waste before adding it to the compost heap. In addition, household and garden waste decomposes best when the different components are alternated. A layer of dry tree or hedge trimmings should be followed by moist plant or kitchen scraps. Fresh grass cuttings should ideally be mixed with shredded branches.
Alternating materials ensures that the compost heats up to around 60 degrees Celsius inside and the green waste decomposes, which will kill harmful organisms.
Turn and sift twice a year
In between, however, the layers need to be turned so that the microorganisms in the mixture get fresh air and the decomposition process keeps going. The FNR experts advise turning the heap twice a year – ideally in spring and autumn, when trees and hedges are cut and there is a particularly large amount of new green cuttings to mix in.
When turning the pile, the material already on the compost should be passed through a sieve – what comes out at the bottom is ready for the garden. Anything that is still too big goes back into the composter. The coarsest material goes to the bottom, followed by dry and moist layers alternating with smaller material.
The more often you turn the pile, the faster the composting will happen, say the experts.
