Tone it down: Why too much artificial lighting is bad for your garden

Living deep in the Irish countryside as I do, surrounded by a centuries-old patchwork of farm fields, hedgerows and leafy pockets of ancient native woodland, a clear winter night sky is a thing of profound beauty. It is filled with the otherworldly shimmer of a host of constellations, familiar to me from my childhood.

Orion’s Belt, with its three supergiant stars Alnitak, Alnilam and Mintaka, neatly aligned in a row, is easy to spot. So too is the Plough, its seven stars roughly forming the shape of a saucepan, and pointing the way towards the North Star, Polaris, situated just above the North Pole. Nearby is the W-shaped star-rich constellation that is Cassiopeia, and Castor and Pollux, the twin half-brothers of Greek mythology. And of course the moon, the earth’s natural satellite, neither a planet nor a star, but the brightest and largest of them all.

Sadly, for those living in cities or large towns, it’s increasingly rare to get the opportunity to enjoy this celestial spectacle in full, its beauty often dimmed to the point of near-invisibility by the light pollution that’s become so much a part of the 21st-century urban landscape. Putting the magic and majesty of a starry winter night sky aside, the myriad of complex ways in which artificial light pollution or ALAN (artificial light at night) also affects the natural world by disrupting the ebb and flow of its ecosystems, from the migratory patterns of birds to the life cycles of invertebrates, is only beginning to be properly understood.

According to one study, for example, it’s estimated that up to a third of all flying insects attracted to street lights will die as a result. That long list includes beetles, lacewings, aphids, crane-flies, bees, moths, butterflies,