We produce several tonnes of compost every year. Most is used to keep the soil healthy and fertile for crop production, but we also use fractions of certain materials for plant raising and so we are self sufficient in propagating compost/plant raising growing media.
We usually make three different kinds of compost on site: Garden compost made from post harvest trimmings/crop matter and weeds; composted manure from local horses; and leafmould from leaves within the grounds.
Onions and leaf crops growing in modules prepared with the leafmould/manure/sand mix. Small modules and less demanding crop types will grow well in a two-thirds leafmould to a third manure (+ sharp sand) as long as they are planted out in time. Otherwise a liquid feed made from on site plants such as nettles and comfrey, or bought-in seaweed extract, may occasionally be employed.
Nutrient requirements of the crop, and the size of pot/module employed determines growing media proportions. These squash and capsicum seedlings, for example, are growing in a mix of half leafmould, half manure (+ sharp sand).