Helping Pollinators at a Field-scale

Pollinator food

Pollinators need a good supply of food (nectar and pollen) from early spring through to late autumn. Current research suggests that by managing 2% of arable land as flower-rich habitat, local populations of pollinators can be boosted and total crop yields improved. As different species of pollinator feed on different flower species, for example long-tongued bumblebees like ‘tubular’ flowers (such as legumes and yellow rattle) and short-tongued bees like open-fronted flowers (such as fruit trees, knapweeds, umbellifers and brambles), you should try to provide a range of different wildflowers, shrubs and trees. At a field-scale you can achieve this by:

• Managing existing wildflower-rich grasslands to maximise flowering through the season.  If possible delay cutting of hay meadows to allow later flowering species to flower and set seed. On pastureland implement lighter grazing regimes and/or no grazing periods to increase flowering. Light cattle grazing will generally allow more plants to flower than sheep grazing. These permanent grasslands will sustain good populations of wild pollinators, which can spread into other parts of the farm.
• Increasing the range of flowers in other permanent grassland areas (meadows and pastures) by reducing inputs of fertiliser and/or over-seeding with locally-sourced wildflower seed. Grazing levels should be reduced in summer months to encourage flowering of plants such as clovers, yarrow, dandelion, common bird’s-foot trefoil, meadow vetchling, and buttercups.
• Sowing legume and herb-rich swards rather than pure grass mixes. Legumes are especially important for bumblebees. Flying places huge energy demands on pollinating insects so areas devoid of flowers can significantly restrict their movement. Sown wildflower mixes should include a range of species that will flower sequentially and can benefit pollinators that are both long-tongued (many bumblebees) and short-tongued (most hoverflies).
• Establishing flower-rich margins or plots to provide additional pollen and nectar resources. Combining permanent wildflower margins with other pollinator friendly features (such as tussocky grass margins, hedgerows and ditches) will produce increased benefits for wild pollinators.  Flower-rich margins can be either sown (ideally using locally sourced wildflower seed) or allowed to develop on bare disturbed soils through natural regeneration.
• Planting pollen and nectar mixes. These can provide wonderful and long displays of flowers, and large quantities of nectar and pollen resource.
• Taking low yielding or difficult to manage field corners out of production and leave them to naturally regenerate with vegetation. Locate these unmanaged field corners to provide buffers alongside hedgerows, woodlands or ditches. The mix of nectar-rich tall herbs which will grow in these areas, including hogweed, cow parsley and vetches provide excellent food sources for wild pollinators.  In the longer-term other important food plants such as bramble and hawthorn may also develop, and this range of plants will help provide a long-lasting supply of nectar and pollen. Cutting these areas infrequently (every two or three years) or in rotations will increase flowering periods.
• Managing hedgerows on a two or three year rotation, as this will encourage flowering and also save you money. Hedge bottom plants such as red dead nettle, ground ivy, hogweed and cow parsley all provide vital food for pollinators, so protect flower-rich hedge bottoms with buffer strips, by taking field corners out of management or by using fencing to exclude grazing animals. When planting new hedges use a variety of species to provide a long flowering season. Species such as blackthorn and pussy willow provide early food, while flowering ivy will provide food long into the autumn.

Sheltering and nesting places

Pollinators also need sheltering and nesting sites, such as scrub and hedgerows, rough tussocky grassland, earth banks and unsprayed conservation headlands. At a field-scale these can be provided by:

• Creating or maintaining tall grown tussocky grass margins to provide important nesting and over-wintering areas for wild pollinators. Ideally cut these areas on rotation or in sections, which will provide longer areas of vegetation including woody stems and seed heads that can be used for shelter. Combining these areas with permanent or temporary wildflower margins, or hedgerows to create a mix of habitats that provide  food, nesting and shelter will also mean emerging insects do not have far to fly for food.
• Keeping earth banks and dry ditches in or around fields. These are often used by small mammals like voles to create their burrows and once abandoned these homes are often re-used by wild pollinators such as bumblebees for their own nesting sites. Avoid disturbing nesting sites (both in bare ground and tussocky grass) between March and October.
• Including some winter stubbles in your cropping pattern. These areas along with unsprayed conservation headlands will provide important refuges for pollinators, as the woody plant stems can be used for over-wintering.
• Keeping any standing and fallen deadwood and in-field and hedgerow trees to provide nesting areas. These habitats, along with hedge and ditch banks will often be used by overwintering pollinators, and decaying wood can provide important breeding sites for hoverflies and other invertebrates
• Cutting hedgerows on a two or three year rotation to encourage development of a thick structure. Hollow twigs and dead wood in hedges can provide useful nesting sites for pollinators such as bees and wasps. Keep grazing animals away from hedge bottoms, as leaf litter and other dead plant material will provide overwintering sites for a range of insects.

For more detailed information on managing individual habitats on farmland for invertebrates visit our habitat pages for grassland, woody habitats, arable land, and wetlands and water