These are typically a mix of legumes including clovers, trefoil and vetches. This is one of the most crucial agri-environment options, helping to encourage a broad range of insects that are of conservation interest or perform essential functions, such as pollination and pest control. A wide range of insects feed on pollen and nectar, but it is especially important for bumblebees, butterflies and moths, all of which are in serious decline on farmland.
Some of the legumes are also important host plants for butterflies. The reproductive capacity of insects which help control crop pests, for example hoverflies and parasitic wasps, is improved when they have access to flowers.
Establishment and management
Fodder varieties are usually sown as these are much cheaper than native ones. Seed mixes must contain at least three species under ES regulations, but more species is better, selecting them to maximise the period over which the area is in flower. The flowering period can also be extended by cutting half the area in June. Seed mixes are available with and without grasses, but the grasses usually start to dominate the sward after two years and we now recommend sowing just legumes.
An autumn cut, done when the legumes have finished flowering will also help prevent grasses from establishing. Existing swards can be rejuvenated by applying a clover-safe gramminicide in early spring.
To reduce competition from annual weeds, the seed should be sown into a weed free seed bed, preferably after a stale seedbed. Avoid sowing after broadleaf crops to reduce the risk of volunteers. Sow either between March and May or July and mid-September.