In the industrialised valleys of South Wales at the start of the nineteenth century there was a tradition among coal miners to garden at night. Hardly pausing to brush the coal dust from their hands after a hard day's work, the miners would turn their soil, sow, weed and harvest by the light of the moon, creating a small patch of vegetables to supplement their income.

Human eyes cannot detect colour without light. In darkness all the colours disappear. All that is left is the contrast between black and white. The world these men inhabited was one of almost perpetual darkness and night shadows. Biologically speaking, apart from holy days and holidays, their lives were spent without colour.

For most gardeners – and publishers of coffee table gardening books – a life bereft of colour is a dismal prospect. But, as most of us have about as much daylight time in our gardens now as the 19th Century miners, this is a shame. How much nicer would it be to return from a nine hour day (and commute), to a garden that is grown to benefit you at the time you can most enjoy it (if you're anything like me, that's at about nine o'clock in the evening)?

Throughout the summer months, nine o'clock is a great time to be in the garden. The garden is already full of scent released from evening and night-scented flowers, moths are starting to arrive to feast on the nectar, the odd daytime visitor (bees primarily) can be seen browsing the flowers for a last minute harvest. From my garden overlooking the Dyfi estuary I can usually hear a song thrush. When night falls an owl calls.

Of course, it is not as idyllic as it sounds. I also share my garden with a group of midges, and they quite like nine o'clock, too. Not only that, but Wales' wettest month is usually August. And, when the night is clear, it's usually much colder than I would like.

By ten o'clock, though, the midges have all gone, I've lit the candles, stoked the kindling fire and the night has begun. Straight away I can appreciate the simple, stark clarity of white flowers set against dark foliage. My wild strawberry flowers are breathtaking. They protrude on stalks in clusters of six or seven from the forest of leaves beneath. Around about eleven o'clock they start to look like constellations.

By then the moths have broken cover. It's great to see a hedgehog in your garden, or a fox or a badger, but, let's face it, for most of us this doesn't usually happen. If you want to watch something really interesting every night, go for something smaller. I am always amazed by the lack of attention moths receive among gardeners.

They are fantastic pollinators, and there's not a moment on earth when they or their offspring are not being eaten by some passing bird, mammal, insect, arachnid or amphibian. Perhaps it is old-fashioned prejudice that keeps people from enjoying this ancient insect, but, for truly impressive garden biodiversity, you can't beat the moth. There are over 700 species of so-called macro moth in Britain and another 1300 micro moth (compared with only fifty-plus butterflies), and many of these are quite happy in gardens. In fact, much happier than most hedgehogs, badgers and foxes.

Having spent much of the last six months working on my new book Curious Incidents in the Garden at Night-time I have had some very interesting times exploring my garden in a completely new way. One of the highlights has been watching an Emerald moth rest on the buckle of a friend's belt as if it were a jewel. The moment filled me with calm wonder. I will never forget it.

Allan Shepherd's new book Curious Incidents in the Garden at Night-time is available from the 6th October from CAT Mail Order (Tel: 01654 705959, £8.99 plus £4.00 postage), or from any high street bookshop.