Why hedgerows are the best investment you can make for garden birds

A good hedgerow does three jobs at once. It gives birds somewhere safe to build a nest, somewhere to shelter from wind, rain and cats, and a larder of berries, seeds and insects through the year. Nothing else you plant in a British garden works quite so hard for so little effort.

Native shrubs beat exotic ones here, and it is not simply sentiment. Our birds evolved alongside hawthorn, blackthorn and hazel, so they recognise the architecture, the nesting niches and the timing of the food. A mixed native hedge also supports the caterpillars that tits and robins rely on to raise a brood — a single oak or hawthorn can host dozens of species that a laurel or leylandii never will.

If you have room for just one hedge, plant hawthorn. If you have room for a stretch of five or six metres, mix three or four species for structure, staggered flowering and a longer season of food.

Hawthorn: the backbone of any bird hedge

Hawthorn (Crataegus monogyna) is the classic hedgerow shrub, and for good reason. Its dense, thorny growth makes a nest almost impossible for a predator to reach into, and its May blossom is followed by haws that feed blackbirds, song thrushes, redwings and fieldfares well into winter.

Robins, dunnocks, chaffinches and blackbirds all nest in hawthorn. Later in the season, blue tits and great tits hunt its leaves for caterpillars. Left to grow tall — two to three metres — it produces the sort of deep, layered canopy that long-tailed tits love for their elastic, lichen-covered nests.

• Plant bare-root from November to March for the best value and establishment.
• Space plants 30–45cm apart in a double row for a thick, stock-proof hedge.
• Cut only in winter, after the haws have been eaten, and never between March and August.

Blackthorn: early cover and a sloe harvest

Blackthorn (Prunus spinosa) flowers on bare wood in March and April, often before hawthorn has a leaf on it. That early nectar is a lifeline for queen bumblebees, and the shrub's fierce spines make it one of the safest nesting sites in the garden.

Whitethroats, dunnocks and robins nest low in blackthorn, and its dense suckering habit creates the tangled base that wrens and hedge sparrows slip into. The sloes that follow in autumn are too bitter for most birds until frost softens them, but thrushes and winter visitors will strip them eventually.

Blackthorn is a suckering shrub, so give it space or keep it at the end of a hedge where it can spread without swamping finer plants. It also grows happily on heavy clay, which makes it useful on the sort of soil many UK gardens have. Wear thick gloves when you prune — the spines go straight through thin ones.

Hazel: catkins, nuts and nesting shelves

Hazel (Corylus avellana) brings something different to a hedge. Its leaves are soft and palatable to moth caterpillars, its February catkins are an early source of pollen, and its nuts are prized by nuthatches, jays, wood mice and, if you are quick, your neighbours. Squirrels will take most of them, but that is part of the point.

Hazel's structure is its secret for birds. It grows in a vase shape, sending up many stems from the base, which creates sheltered forks and ledges. Robins and chaffinches nest in these, and the leafy canopy offers cover for foraging blue tits and great tits.

Coppicing hazel on a rotation — cutting a third of the stems to the base every few years — keeps it bushy and productive rather than leggy. Do this in winter, and avoid the nesting season entirely.

Good companions to mix in

A hedge of a single species is fine; a hedge of four or five is a small nature reserve. These native shrubs all earn their place:

• Field maple (Acer campestre) — excellent autumn colour and a favourite of aphids, which means caterpillars and tits follow.
• Guelder rose (Viburnum opulus) — white lace flowers, translucent red berries that bullfinches and mistle thrushes take in autumn.
• Dog rose (Rosa canina) — thorny, scrambling cover, plus hips for redwings and waxwings in a hard winter.
• Honeysuckle (Lonicera periclymenum) — a climber, not a shrub, but it weaves through a hedge and its scent draws moths and the birds that eat them.
• Ivy (Hedera helix) — flowers in late autumn for bees, berries in spring for blackbirds and thrushes, and superb dense nesting cover.

If you garden on sandy or chalky soil, add spindle and wayfaring tree; on damp ground, alder buckthorn is worth a go.

Planting and looking after it for birds

Bare-root hedging planted between November and March is cheap, establishes fast and rarely needs watering beyond the first summer. Prepare a strip about 60cm wide, clear the grass, and mulch with well-rotted manure or bark. Water well for the first two growing seasons, then leave it alone.

The single most important rule is this: do not cut your hedge between March and August. That is when birds are nesting, and hedge trimmers and nests do not mix. Even the tidiest-looking hedge can hide a robin's nest deep inside. Prune in January or February, or leave it until September once the berries have gone.

When you do trim, aim for a slightly A-shaped profile — wider at the base, narrower at the top. Light reaches the bottom, the hedge stays thick to ground level, and you get far more nesting space than from a flat-topped block. Cutting every second or third year rather than annually lets flowering and fruiting wood build up, which means more haws, sloes and nuts for the birds.

Finally, resist the temptation to tidy the leaf litter and dead stems beneath the hedge. That layer is where dunnocks, wrens and blackbirds forage, and where a great many insects spend the winter. A little mess at the base of a hedge is one of the most productive habitats in the garden.

Plant it, leave it alone, and within two or three springs you will hear the difference — a hedge full of birdsong is one of the great rewards of a wildlife garden.