Growing a variety of crops specifically for compost making ensures a good supply of green material and it provides a diverse diet for the microorganisms in the compost pile.
If you have limited space you can grow these crops in between ornamentals or you can grow them in the food garden during the cooler months. In larger food gardens we devote specific beds to year round compost crop production.
When sowing the crops you can mix the seeds that go into the bed and you don’t need to worry too much about spacing. Most food gardeners mix the seeds beforehand and then broadcast sow them into the beds.
A good mix during autumn and winter is fava beans (a.k.a. broad beans or ‘boer bone’), peas and herbs such as borage and rocket. In large gardens wheat can be added to the mix. All these crops are very good energy-traps (they produce lots of compost material) without taking too much from the soil. You’ll find seeds at the agricultural co-op.
Compost crops will need to be ‘harvested’ whenever they reach a height of 30cm to 45cm. Do not pull out the crops, cut them about 10cm from soil level. Never allow your compost crops to flower and set seed as this will take too much nutrients from the soil, and it may cause one or more crops to become ‘weeds’.