Georgina Fairfax
Why a Mixed Hedgerow Is Britain's Busiest Wildlife Corridor
A hedgerow is never just a boundary. A well-grown mixed hedge of hawthorn, blackthorn, hazel, field maple, dog rose and honeysuckle, with the occasional oak or ash standard left to grow tall, offers food from March right through to January. Blossom comes first, then leaves for caterpillars, then berries and nuts for birds and small mammals. The dense base of tangled grass and leaf litter beneath it is a nursery, a larder and a hibernation site all at once.
That layering is the point. A single-species hawthorn hedge trimmed to the same height every year gives far less than a mixed one cut on a rotation. Wildlife moves along hedges as though along a railway line, travelling from wood to copse to garden without crossing open ground where they are exposed. If you want to see more than the occasional wood pigeon, find a hedge that has been allowed to grow thick and uneven, ideally one with a grassy margin on either side.
Follow the Blossom: Brimstones and Early Bees
The brimstone is usually the first butterfly of the year, often on the wing in a warm spell in March before any leaves have opened on the blackthorn. Males are a clear sulphur yellow and patrol the hedge line restlessly; females are a paler greenish white. They feed on dandelion, bugle and early thistle, and their caterpillars need alder buckthorn or purging buckthorn, both of which still turn up in old hedges in southern England and Wales.
Once the blackthorn and hawthorn are in flower, look along the sunny side of the hedge in the middle of the day:
- Orange-tip butterflies, nectaring on lady's smock and garlic mustard in the hedge bottom
- Tree bumblebees and early mining bees working the blossom
- Comma and peacock butterflies later in summer, drawn to bramble flowers
- Red admirals on ivy flowers in September and October
Berries, Nuts and the Mammals That Rely on Them
The hazel dormouse is the headline act, and the one you will almost certainly never see. It is small, golden and nocturnal, and it depends on exactly the sort of hedge described above: hazel for nuts, honeysuckle for bark to strip for nesting material, bramble for thorns to hide in, oak for caterpillars. It hangs on chiefly in southern England and parts of Wales, and the best way to record one is by its field signs in autumn.
Look for hazelnuts with a neat, round hole and fine tooth marks around the rim — quite different from the jagged, chiselled hole left by a wood mouse or the split shell left by a squirrel. Sloe stones and cherry stones gnawed in the same tidy manner are worth noting too.
Hedgehogs work the same hedge bottoms at night, nosing through leaf litter for beetles, caterpillars, slugs and earthworms. They nest under the thickest, oldest section of hedge and hibernate there from around November. A quiet walk with a torch at dusk in late summer, especially after rain, is the simplest way to find one. Wood mice, bank voles and shrews are far commoner and give themselves away with a rustle in the dry leaves at the hedge base.
Birds That Announce the Hedge Before You See Them
The yellowhammer's song is the sound of a mixed hedgerow on a May morning — often written down as "a little bit of bread and no cheese", delivered from the top of a spray of hawthorn. It needs hedges with a good grassy margin for nesting on the ground and for seed in winter.
Other species to listen and watch for:
- Whitethroat, singing from the top of bramble and hawthorn, often with a scratchy, scolding finish
- Dunnock, creeping about under the hedge itself rather than above it
- Wren, usually heard before seen, rattling from deep cover
- Linnet and bullfinch, the latter feeding on buds in late winter
- Song thrush, with a favourite stone for smashing snails near the hedge line
- Redwing and fieldfare, stripping haws, hips and sloes in hard weather
How to Walk Quietly and Look Closely
Most people walk past hedges far too quickly. The trick is to move in short stages, pause often, and let your eyes drift along the hedge rather than the path ahead.
- Go early. Between May and July, the first hour or two after sunrise is when hedgerow birds are singing and insects are still sluggish enough to watch.
- Keep the sun behind you where you can. It lights the face of the hedge and makes movement in the foliage far easier to pick out.
- Use binoculars with a close focus of two metres or less. They turn a hedge into a series of small rooms.
- Stand still for a full two minutes at each stop. The rustling usually resumes once you have stopped moving.
- Keep dogs on a lead and stay off the hedge base itself — that tussocky strip is where the nests are.
- Carry a torch at dusk for hedgehogs, and a hand lens for nuts, galls and leaf mines.
Give a Hedge a Chance
If you look after a hedge, or can ask a landowner to, the single most useful change is to cut it on a rotation rather than every year. Trim no more than a third of the hedges on a holding in any one winter, and leave the rest for two or three years to flower and fruit. Cutting should be done in late winter, between mid-January and the end of February, and never between March and August, when nesting birds are protected by law.
Let one hedge grow tall and bushy beside a low, dense one, and leave the base untouched so it keeps its grassy skirt. Plant up gaps with native species — hazel, field maple, dog rose, guelder rose, spindle — and leave a small pile of cut wood nearby. Within two or three seasons you will notice the difference: more blossom, more berries, more birdsong along that stretch, and a hedge that has quietly become a habitat again.
