What
Retaining any existing flower-rich field margins and creating new perennial margins using a mix of native grasses and flowering plants will increase the availability of pollen and nectar for beneficial insects.
If at least 1% of arable farmland can be managed to support flowering plants, this will help to boost populations of pollinators, crop pest predators and a wealth of wildlife that are dependent upon them.
Why
Field margins are generally the least productive areas of a field and management of these areas for wildlife can improve the gross margins of arable cropping as well as supporting beneficial insects to improve crop pollination and pest control.
How
Firstly, identify and maintain any existing flower-rich habitats on farm. Flower-rich grasslands and margins are best managed by cutting and removing (or grazing) the vegetation after flowering plants have set seed.
Flowering within hedgerows can be increased by cutting as infrequently as possible, or at least avoiding annual cutting of flowering shrubs such as hawthorn and blackthorn.
- Create wild flower strips within a 6m margin or in blocks of at least 0.25 ha.
- Choose a warm, sunny area (e.g. sheltered, south-facing slopes) where insect activity will be greatest. Well-used farm tracks and footpaths are good sites as these areas are disturbed too often to make them suitable for the tussocky margins that suit nesting birds.
- Close proximity to rough grass margins is important for some insects to nest, such as bumblebees.
- Seek advice to find out if there is local seed available.
- Leave an area to regenerate naturally if a perennial grass sward will develop; otherwise drill a native seed mix.
- Autumn (August/September) is the best time to establish wildflower margins; use a higher seed rate if sowing in spring.
- Use a mix of fine grasses, such as fescues and bents. Wild flower seed should comprise between 5% and 20% of the mix by weight and include native plants such as yarrow, knapweed and ox-eye daisy.
- Spray a heavy weed burden with glyphosate or glufosinate before cultivation.
- Drill the grass seed and broadcast the wild flower seed into a fine, stale seedbed before rolling.
- Cut the sward when it is 10cm tall in the first summer to control weeds and encourage grasses to tiller; this may require three cuts. Swaths of cut grass lying on top of the sward may suppress the perennial grasses and wildflowers – it is better to cut and remove the vegetation if machinery is available to do this.
- Apply no fertiliser or pesticides: wildflowers thrive in nutrient-poor soils. If necessary, control weeds by cutting or spot-spraying.
- Avoid herbicides and fertiliser drifting into the margin as these will benefit competitive weeds over perennial grasses and wildflowers. Insecticide drift harms any beneficial insects supported by the field margin.
- Treat barren brome in the grass margin selectively with an application of fluazifop-P-butyl in November (most perennial grasses will recover from this treatment).
- Cut and ideally remove the vegetation annually in the autumn.