Why look closer at your garden

A sunny afternoon in a British garden can hold more butterflies than most people realise. Between May and September, a modest patch of flowers and a few metres of hedge can support eight or ten species, and on a really good day you might catch a dozen without leaving your lawn. The trick is knowing what you are looking at. Most people recognise a "cabbage white" and stop there, but half the pleasure of watching butterflies is learning the handful of species that turn up again and again, and understanding what each one is doing in your patch.

Butterflies are also honest indicators. Where they thrive, there are usually healthy plants, unfussy corners and a bit of shelter. Learning to identify them is really a way of learning what your garden is doing right.

The three you are most likely to meet

Three species dominate British gardens, and each has a foolproof feature to look for.

Peacock. Unmistakable at rest: deep red wings with four bold eye-spots, one on each corner. When it folds its wings, the underside is almost black, which is how it spends the winter tucked into sheds, garages and hollow trees. Watch for it coming out of hibernation on the first warm March days, then again from July when the new generation emerges. It is a buddleia fanatic.

Small tortoiseshell. Bright orange, with black and yellow patches near the leading edge and a row of blue crescents along the wing border. Smaller than a peacock and far more restless. It also hibernates as an adult, often indoors, and its caterpillars feed in dense webs on stinging nettles. If you have a sunny patch of nettles you have not got round to cutting, you have probably already bred some.

Comma. The one people most often mistake for something tattered. Its wing edges are deeply ragged, and it looks as though a bird has had a go at it. Look for the row of small white commas on the underside when it closes up. The clue is in the name. In late summer a second, darker brood appears, and comma numbers have risen sharply in recent decades.

Buddleia: the butterfly magnet

If you want several species at once, plant a buddleia. A single large bush in full sun, in flower from July into August, will often hold a peacock, two or three small tortoiseshells, a red admiral and a comma simultaneously, all jostling for the best spike of purple flowers.

A few practical points. Give it full sun and shelter from strong wind, because butterflies will not settle in a gusty spot. Cut it back hard in March, to about 60cm from the ground, since it flowers on new wood. Deadhead the faded spikes through the summer and it will keep producing fresh ones into September. Space is a limiting factor in smaller gardens, so if you only have room for one shrub, this is the one.

Other regular garden visitors

Once your eye is in, the list grows quickly. These are the next most likely sightings.

• Red admiral. Black wings crossed by red bands and tipped with white spots. A strong migrant that increasingly overwinters here. Fond of fallen fruit as well as flowers.
• Large white and small white. The classic "cabbage whites". Both lay on brassicas, so if you grow kale or sprouts, expect company.
• Green-veined white. Soft cream wings with green-grey veins underneath. Commoner in damp, wilder corners than on your vegetable patch.
• Holly blue. Small, silvery-blue, flies high around holly in spring and ivy in late summer. The first blue of the year in most gardens.
• Speckled wood. Brown with cream spots, dancing in dappled shade along hedges and fences. It rarely visits flowers, so look for it on the wing rather than on a bloom.
• Meadow brown and gatekeeper. Browns of long grass and rough edges. The gatekeeper has two small white dots in each orange patch; the meadow brown has one, or none.

Telling tricky pairs apart

Two confusions trip up most beginners. First, small tortoiseshell against painted lady. The painted lady is a migrant, larger, with a more washed-out orange and black wingtips speckled with white; the tortoiseshell has those blue crescents and yellow patches. Second, comma against a ragged small tortoiseshell. The comma's white mark on the closed wing settles it, and its flight is different too, a sharp, jerky flick that snaps shut and open.

A useful habit is to note three things before you reach for a book: the date, whether the butterfly was basking with wings open or closed, and what plant it was on. Those three details will identify most garden sightings on their own.

Getting more of them next summer

Butterflies need two things from a garden: nectar for the adults and the right leaves for the caterpillars. Most gardens are short on the second.

Leave a sunny patch of nettles at the back of a border for peacocks, small tortoiseshells and commas. Allow ivy to flower in autumn, which is a lifeline for late red admirals and holly blues. Add nectar plants that flower across the season rather than all in one fortnight: lavender and marjoram in midsummer, sedum and verbena in late summer, asters into autumn. Resist the urge to tidy every seedhead in October, since many are winter shelter.

Finally, pick your moment. Butterflies are most active between mid-morning and mid-afternoon on warm, still, sunny days, and they disappear the moment cloud covers the sun. Choose the right hour on the right day, and your garden will seem far richer than it did last week.