Special uses of green manuring
One form of green manuring for a special purpose is the placing of small amounts of grassin the drills when planting to prevent common scab disease. It is effective for this purpose because the fungus responsible for this disease attacks the grass in preference to the potatoes.
Mustard used as ahas an additional value in controlling pests. If you have a garden or allotment that was only recently taken over from grassland, it is likely to contain numbers of wireworms. These pests, which are the larvae of click beetles, attack the roots of vegetables, particularly potatoes, root vegetables and . If you grow and dig in a patch of , however, the wireworms will attack this rather than your crops.
Buckwheat may also assist in controlling pests, by acting as a host plant to the larvae of hoverfiies, which eat large amounts of greenfly.
Obtaining the seeds
As mentioned above, several seeds such as mustard, rape and winter, are easily obtainable from garden shops and nurseries, but the rest are more difficult to obtain in the small quantities required by gardeners. Farm nurseries only sell the other seeds mentioned in bulk and rarely in quantities less than 3 kg (7 lb). It is a good idea for horticultural and allotment societies or more informal groups of gardeners to buy in bulk at the rather cheaper rates and distribute them individually. Commercial suppliers and farm nurseries will be pleased to deal with large orders from groups or societies.