Planting a hedge to support rare invertebrates

Why a native hedge is more than a boundary

A hedge is one of the hardest-working habitats in a British garden. For rare invertebrates it is a larder, a nursery, a corridor and a winter shelter rolled into one. Our hedgerows have declined dramatically over the past century, and with them have gone the specialists that depend on native shrubs: the brown hairstreak butterfly, which lays its eggs on young blackthorn; the hazel pot beetle, which shelters in coppiced hazel; and countless moths, beetles, bees and flies that need particular leaves, nectar or deadwood. Even a five-metre run of native shrubs in a garden can join the dots between larger fragments of habitat.

Choose the four cornerstone species

For rare invertebrates, the species you plant matter more than the number. A mix of hawthorn, blackthorn, hazel and field maple gives year-round value, with different flowers, leaves, fruits and growth habits. Plant them in informal blocks or drifts rather than a rigid alternating pattern.

• Hawthorn (Crataegus monogyna) — The backbone of most traditional British hedges. Its dense, thorny growth protects nesting birds and shelters invertebrates. Spring flowers feed early bees and hoverflies, and the haws feed birds into winter. It supports a vast number of moth caterpillars, including scarce species.
• Blackthorn (Prunus spinosa) — Essential for the brown hairstreak butterfly, which lays eggs singly on young stems. Its white, starry flowers appear before the leaves and are a lifeline for queen bumblebees. Sloes follow in autumn. Give it sun and allow some young growth to remain uncut.
• Hazel (Corylus avellana) — Valuable for its late-winter catkins, when little else flowers, and for its leaves, which feed several specialist moths. It creates sheltered, humid conditions at the hedge base. Traditional coppicing every few years produces a mosaic of ages that suits invertebrates.
• Field maple (Acer campestre) — Our only native maple. Its small greenish flowers are visited by bees and hoverflies in late spring, and its leaves turn buttery gold in autumn. It supports the maple prominent moth and adds compact, twiggy density. It tolerates clipping and heavier soils.

Planting for a long, wildlife-rich life

Plant bare-root whips between November and March, when the ground is frost-free and plants are dormant. Choose British native origin where possible, and look for 60–90cm whips with a good root system. Clear a strip at least one metre wide — competition from grass is the main reason young hedges fail. Improve poor soil with well-rotted compost, but avoid rich fertiliser, which encourages soft growth at the expense of flowers and fruit.

For a thick hedge, plant a double staggered row: 30–45cm between plants and 40cm between rows, giving five to seven plants per metre. A single row at 45–60cm spacing works for a looser hedge, but the double row shelters more invertebrates. Firm the soil, water well, and mulch with bark chip or compost, keeping it clear of stems. Water for the first two summers and keep the base clear of grass until established.

Manage it like a habitat, not a topiary

How you cut a hedge can make or break its value. Avoid cutting between March and August, when birds nest and invertebrates are active. Cut in late winter instead, ideally every second or third year, and never flail the whole hedge at once. Trim one section each year on rotation, leaving some areas to flower and fruit. This creates a mix of ages and heights, suiting species that need young growth, such as the brown hairstreak, as well as those that need older, denser cover.

Leave trimmings in a loose pile at the base for a few days, or tuck them into a corner, so invertebrates can crawl back. Allow ivy, bramble and native wildflowers in the hedge bottom — these are habitat, not untidiness. Bramble flowers feed nectar-loving insects, and its tangled stems provide overwintering sites. Deadwood, leaf litter and mossy bases all play a part. Avoid pesticides and herbicides near the hedge.

Small gardens, big difference

You do not need acres. A three-metre hedge of hawthorn, blackthorn, hazel and field maple can be kept to two metres high and still support a surprising range of invertebrates. If space is very tight, choose one or two species and manage them as a loose, informal screen rather than a tight box. Add native climbers such as honeysuckle or wild rose through the hedge for extra nectar and shelter. In the shade at the base, plant native woodland-edge plants like wood avens, red campion or foxglove, and leave a patch of bare earth for solitary bees.

Rare invertebrates are often specialists, and specialists need continuity. A hedge planted this winter will take a few years to become truly useful, but it will improve with every season. By choosing the right native species, planting them well and managing them gently, you create a small living corridor that helps rare wildlife move through a fragmented landscape. That is conservation you can do with a spade, a pair of gloves and a little patience.