Why Moths Are the Quiet Stars of an Evening Garden

Britain has around 2,500 species of moth, and only a tiny handful ever trouble a wardrobe. The rest are pollinators, food for bats and nestlings, and some of the most beautifully marked insects you will ever see at close range. If you have planted night-scented stock, honeysuckle or evening primrose, the chances are they are already visiting after dark — you have simply never been introduced.

A torch-and-sheet survey is the gentlest way to meet them. Nothing is killed, nothing is kept, and everything goes back to the hedge within minutes. It also turns an ordinary warm evening into something you will look forward to all week.

What You Will Need

• A white cotton sheet, ideally at least 2 metres square — old bed linen is perfect
• A bright LED torch, plus a dimmer one for close inspection
• A head torch, so both hands stay free
• Pegs, string or a couple of clothes props
• A soft artist's brush and a clear jar or tub with air holes punched in the lid
• A notebook and a pencil

That is genuinely it. Purpose-built light traps catch far more, but they also hold insects for hours, which is more than a casual survey needs. A sheet is a resting place, not a cage.

Setting Up for a Good Night's Mothing

Choose a still, mild evening — ideally above 10°C, with cloud cover and a touch of humidity. Wind, heavy rain and clear bright moonlight all suppress activity, so a dark, muggy night after a warm day is your best bet. Late spring and high summer are peak months, though there is something flying from March right through to November.

Hang the sheet vertically against a fence, hedge or washing line, with the bottom edge touching the ground or a groundsheet. Drape it loosely so it has folds and creases. Peg it firmly — a flapping sheet frightens off more moths than it attracts.

Place the torch so it shines directly on to the fabric, roughly a metre away, and angle it slightly downwards. Switch off nearby garden lights and close the curtains behind you; contrast is everything. Then step back, sit quietly, and give it a good twenty minutes.

If you want to boost numbers, hang a wine rope nearby — a length of cloth soaked in red wine and sugar and left to ferment for a day or two. It is entirely optional, and the plain light will do perfectly well on a good night.

Watching, Noting and Identifying

Moths arrive in waves rather than a steady trickle. Check the sheet every fifteen minutes or so, using the dim torch so you do not startle anything. Look at the folds first, then the edges, then the ground beneath.

Note down what you see before you try to name it. Useful details include:

• Wingspan, roughly, measured against a coin or your thumbnail
• Wing shape and resting posture — flat, tent-like, or rolled tight
• Base colour and any pale spots, bands, wavy lines or metallic marks
• The colour of the hindwings, often hidden until the moth moves
• Whether it walks, flutters or sits utterly still

Common garden visitors include the brimstone, the Hebrew character, the common quaker, angle shades, silver Y and the large yellow underwing. A phone photograph taken in daylight-toned light is a great aide-mémoire, and a simple field guide will get you surprisingly far. Do not worry about getting every one right — the point is the survey, not a perfect list.

Handling and Releasing Your Guests

Most moths need no handling at all. If one lands somewhere awkward, coax it gently with the soft brush on to a leaf or into your jar, cap it, look closely for a minute or two, then take it straight out to a shrub and let it walk off on to the foliage.

Never grip a moth between finger and thumb — the scales on the wings rub off at the lightest touch, and those scales are how it flies and stays warm. Keep cats indoors for the evening, and avoid leaving the jar in direct sun or in a cold shed while you finish your notes.

Finish by ten or eleven, switch off the torch, and shake the sheet over the border. Anything still clinging will find its own way home.

Building a Better Survey Next Time

Keep a simple record: date, time, temperature, wind, cloud, and the species you recognised. Repeat it through the seasons and patterns appear — the first brimstone in March, the flush of yellow underwings in July. Your county moth recorder will be delighted with the records, and they genuinely help conservation.

To draw more in, plant for the evening. Night-scented stock, tobacco plants, honeysuckle, jasmine, red valerian and evening primrose all release their scent after dusk and are pollinated by moths. Leave a little long grass and ivy undisturbed, avoid garden chemicals, and your sheet will fill up faster every year.