Gardening with native hedgerows for wildlife

A hedge is a habitat, not just a fence

A close-boarded fence keeps the neighbours out and the wildlife out with them. A mixed native hedge does the opposite. It gives you privacy, a windbreak and a screen, but it also offers blossom in spring, berries in autumn, catkins in midwinter and — most importantly — dense, thorny, tangled growth where birds can nest out of reach of cats and magpies. Even five metres along a garden boundary is worth planting. Do it well and within three or four years you will have more bird activity in that strip than in the rest of the garden put together.

The key is mixture. A single-species hedge of leylandii or privet is a wall. A hedge of hazel, blackthorn and hawthorn is a larder, a nursery and a storm shelter in one.

The three workhorses

Hawthorn (Crataegus monogyna) is the backbone of almost every good field hedge in Britain. It is thorny, tolerant of almost any soil, and supports a quite extraordinary number of insects — well over 300 species of moth and butterfly have been recorded on it. The May blossom feeds early bees and hoverflies, the red haws in autumn keep blackbirds, redwings and fieldfares going through the winter, and the dense twiggy growth is a favourite nesting site for dunnocks, robins and chaffinches.

Blackthorn (Prunus spinosa) flowers earlier, usually in March, on bare black stems — one of the first proper signs of spring in the countryside. It is even thornier than hawthorn, which makes it superb nesting cover, and it carries sloes in autumn. Leave a few for the birds and pick the rest after the first frost for gin.

Hazel (Corylus avellana) brings something different: long yellow lambs' tail catkins in January and February when there is almost nothing else in flower, and nuts in September that are taken by squirrels, wood mice and nuthatches. Its leaves feed the caterpillars of several moths, and dormice — where you are lucky enough to have them — rely on hazel nuts to fatten up before hibernation.

To those three, add any of the following for variety and a longer season of interest:

• Field maple — good autumn colour, seeds for finches
• Dog rose — hips for thrushes, pollen for bees
• Guelder rose — white blossom, translucent red berries
• Crab apple — blossom, fruit, and a lovely gnarled shape
• Holly — evergreen nesting cover and winter berries
• Spindle — vivid pink autumn foliage and orange seeds

Planting bare roots: get it right once

Buy bare-root whips, 60–90cm tall, between November and March, and plant them the day they arrive if you can. A double staggered row is far better than a single line: it gives the hedge depth, so birds can nest in the middle rather than on the edge. Space plants about 40cm apart within the rows, with 40–45cm between the two rows, offsetting them so they form a zigzag.

Prepare a trench about 45cm deep and wide, fork the bottom to break up any pan, and mix in a few handfuls of well-rotted garden compost or leafmould. Plant to the same depth as the nursery mark, firm in properly with your heel, then water well. In the first two summers, water during dry spells. Fit spiral guards against rabbits if you have them, and mulch with bark or compost to keep the weeds down — but leave the grass at the base a little rough and long, roughly 30–45cm, because that tussocky strip is itself valuable habitat for beetles, voles and overwintering insects.

Cutting in rotation: the trick that keeps everyone fed

Here is where most gardeners go wrong. They trim the whole hedge in August or September to make it neat, which removes the berries just as the birds need them, or they cut it hard every year, which stops it flowering at all.

Instead, divide the hedge into three sections and cut one section a year on a three-year rotation. Each year, one third gets cut back hard, one third gets a light trim, and one third is left completely alone. That way there is always dense young growth for nesting, always older wood carrying blossom and berries, and always fruit somewhere along the length. Cut the hard section in late January or early February, before the birds start nesting, and take it down to around 60–90cm from the ground to encourage bushy regrowth.

Hazel responds especially well to this, throwing up long straight stems that you can cut for beanpoles and pea sticks. Hawthorn and blackthorn will both regrow from hard cuts, though blackthorn is slower to forgive you.

A few rules of the shears

• Never cut between March and August — it is an offence to damage or destroy a wild bird's nest while it is in use, and a hedge is the most likely place for one.
• Trim the sides so the hedge is wider at the base than the top (an A-shape). Sun reaches the bottom, growth stays dense to the ground, and you avoid the bare, leggy bottom that plagues boxy hedges.
• Leave the trimmings in a corner as a brash pile, or shred them for mulch. Dead wood is habitat.
• Avoid pesticides anywhere near it, and let a little ivy climb through in places — it flowers late, which is a lifeline for bees in October.

What you will see

The first spring after planting you will notice the blossom. By year three the tits will be working it for caterpillars, and there will be a nesting pair of dunnocks or a blackbird somewhere in the tangle. By year five a mixed native hedge of even modest length becomes a genuine wildlife corridor, linking your garden to the next one and the one after that. On a warm evening in June, stand beside it and listen: the rustle and chatter coming out of a good hedge is the sound of a small ecosystem doing its job.