Heathland is a grazed landscape

Lowland heath looks wild, but it is not wilderness. It is the product of centuries of farming on poor, sandy, acid soils — land that was cleared of woodland, cropped lightly, and then grazed by whatever the commoners could keep. Take the grazing away and the heath does not stay heath for long. Birch, Scots pine and gorse move in within a couple of decades, heather is shaded out, and the whole thing turns quietly into secondary woodland.

Britain holds a large share of the world's lowland heath, and almost all of it needs active management. Grazing animals are the most economical and least brutal way of doing that job, because they do something a flail mower cannot: they make decisions. They choose where to graze, where to dung, where to tread, and the result is a mosaic rather than a lawn.

Choosing the right animal

Cattle, ponies and sheep all graze, but they graze differently, and that difference is the point. Most heaths benefit from a mix.

• Cattle wrap their tongues round tufts of coarse grass and pull. They knock back purple moor-grass and tussocky pasture, break up bracken litter underfoot, and poach damp hollows into bare, muddy patches. Traditional breeds such as Belted Galloway, Welsh Black or British White are thrifty, live out all year and hold condition on forage that would starve a commercial suckler.
• Ponies bite close and hard. Exmoor, Dartmoor, Shetland and Welsh mountain ponies clip the sward short, browse gorse and birch seedlings, and are famously hardy. They are the most effective tool for keeping young scrub in check, provided they are not left on the same patch to hammer the heather.
• Sheep nibble fine and selectively. Hebridean, Herdwick or Manx Loaghtan will take heather tips, grass and tree seedlings, which makes them excellent for knocking back regrowth after scrub clearance. They can strip heather if kept on too long, so short bursts or a rotation suit them best.

What grazing actually creates

The aim is not an even sward. It is a patchwork of heights and ages, and that patchwork is what wildlife uses.

• Bare, warm ground for basking adders and common lizards, for sand lizards on the sandy heaths of the south, and for solitary bees and wasps that need open soil to nest in.
• Short, flower-rich turf where sheep's sorrel, tormentil and heath bedstraw can flower and set seed — the larval food plants of silver-studded blue and grayling butterflies.
• Scrub edges and scattered bushes for Dartford warblers, whitethroats and linnets, while nightjars and woodlarks want bare patches sitting among taller heather.
• Dung and its invertebrates, which feed dung beetles, flies and, in turn, the stonechats and meadow pipits that pick over fresh pats.

Heather itself responds well to this. Young shoots are more nutritious than old woody stems, and light grazing encourages the fresh growth that supports heather beetle, emperor moth caterpillars and the whole chain above them.

Getting the numbers and the timing right

Stocking rates vary with soil, rainfall and what you are trying to achieve, but a rough starting point on a dry lowland heath is around 0.1 to 0.3 livestock units per hectare across the grazing season. Timing matters as much as numbers.

• Winter grazing suits many sites: heather is dormant, ground-nesting birds are absent, and ponies or cattle can work over rank grass without damaging the heather.
• Summer grazing is the tool for scrub control, but keep it light and move animals on before heather is grazed into tight, non-flowering carpets.
• Watch the heather as your gauge. You want a range of ages with some plants flowering every year, not a uniform crew cut.

Practicalities matter. Check fencing before the animals go in, not after. Provide a mineral lick and reliable water. Plan for public access, dogs, gates and the welfare of stock that may be miles from the farm — and remember that on many heaths grazing rights belong to commoners, so agreement and goodwill are as important as any grazing plan.

Grazing alongside other tools

Grazing rarely works alone. It is best used to hold open what mowing, burning, bracken bruising or scrub bashing has already created. A mown strip will green up and scrub over again within a few seasons unless something grazes it. Conversely, grazing without any cutting or burning tends to leave rank, even-aged stands that are poor for invertebrates.

If you walk a heath and see cattle or ponies quietly working across it, you are looking at a landscape being managed, not just preserved. That is the whole trick: a few animals doing a job that has kept British heathland open for thousands of years, and will keep it open for a few thousand more.