Start With the Three You Will See Most

Most garden butterfly sightings in Britain come down to a handful of species, and once you can separate three of them reliably, everything else becomes much easier. The peacock, the red admiral and the small tortoiseshell are the classic trio, found from Cornwall to Caithness wherever there are flowers and a bit of sunshine. They overlap in colour and habit, which is exactly why people get muddled, but each has a marking that settles the identification in a second.

Watch how a butterfly holds its wings, too. Some bask with wings spread flat, others sit with wings closed and show only the underside. Both views matter, so try to get a look from two angles before you decide.

The Peacock: Eyespots That Do the Talking

The peacock is unmistakeable at rest. Its wings are a deep, velvety red with four bold eyespots, one on each wing, each ringed in yellow, blue and black. Those spots exist to startle predators, and they work on people as well — the flash of a pair of eyes as the butterfly opens its wings is genuinely startling.

Peacocks appear as early as March, having hibernated over winter in sheds, garages, hollow trees and log piles. They are often the first large butterfly of the year, basking on warm walls in spring sunshine. A fresh generation emerges in high summer and flies into autumn, feeding hard before finding somewhere cool and dark to sleep through the winter.

If you see a butterfly with dark, almost black undersides and a distinctly ragged, bark-like pattern, sitting closed on a fence or path, you may well be looking at a peacock from below. That camouflage is superb, and it is why so many hibernating peacocks go unnoticed in outbuildings.

The Red Admiral: A Migrant With a Taste for Fallen Fruit

The red admiral is a strong flier and a migrant, arriving from the continent each spring and summer, with increasing numbers now surviving our milder winters here. It is a large, dark butterfly with a broad red band across each forewing and white spots near the wingtips. When it closes its wings, the underside is a mottled grey-brown, patterned like a piece of old bark, with a hint of pink at the edge.

You will often see red admirals doing something the others rarely do: feeding on rotting fruit. Fallen plums, windfall apples and overripe pears left on the grass will pull them in by the dozen in a good autumn. They also feed on sap runs and are fond of ivy flowers late in the year, when little else is on offer.

Their caterpillars live on stinging nettles, usually in a folded leaf near the top of the plant — so a nettle patch really does pay for itself.

The Small Tortoiseshell: Orange, Black and Easy to Misread

The small tortoiseshell is brighter and busier than the other two. Its upper wings are a rich orange with black spots and a border of dark patches edged with small blue crescents. That blue detail is the giveaway. If you can see little blue half-moons along the wing edge, you have a small tortoiseshell.

It is a garden regular from March onwards, often seen basking on paths, gravel or dry earth in early spring. Like the peacock, it hibernates — and it has a habit of choosing houses, sometimes appearing indoors in midwinter when a room warms up. Do not panic if one flutters about your spare bedroom in January; open a window on a mild day and let it find its way out.

Confusion usually comes from faded or worn specimens in late summer, when the orange dulls and the markings blur. Look for the blue crescents and the general smallness — it is noticeably daintier than a peacock.

Other Butterflies Worth Naming

Once the trio is familiar, add these to your mental list:

• Comma: ragged, uneven wing edges, orange-brown, with a small white comma mark on the dark underside. Regular on buddleia and overripe fruit.
• Small white and large white: the "cabbage whites". Small white is daintier with greyer wingtips; large white has a black tip that extends further down the forewing edge.
• Holly blue: silvery-blue, small, flies early and often, usually high around holly and ivy. The first blue of the year in most gardens.
• Meadow brown: brown with a single small eyespot near the forewing tip, fluttering low over lawns and rough grass.
• Speckled wood: chocolate-brown with cream spots, fond of dappled shade, hedges and woodland edges.

Photograph anything you are unsure of and compare markings later. A record of date and plant is far more useful than a perfect image.

Plants That Bring Them In — and Keep Them

Nectar gets adults in; caterpillar food plants keep them around. You need both.

For nectar, the reliable performers are buddleia (deadhead it to extend flowering), lavender, sedum, verbena, marjoram, scabious, knapweed and hemp agrimony. Single, open flowers are always better than doubles — doubles often hide the nectar and give insects nothing to land on. In autumn, let windfall fruit lie and leave ivy to flower rather than cutting it back.

For caterpillars, leave a sunny corner of stinging nettles. Most people pull them out on sight; a patch a metre square, in full sun and cut back in midsummer to encourage fresh growth, will support red admirals, small tortoiseshells, commas and peacocks. Add holly and ivy for holly blues, and a few long grasses for meadow browns and speckled woods.

A shallow dish of damp soil or sand gives males somewhere to take up minerals. Skip the pesticides, tolerate a few nibbled leaves, and your garden will do the rest.