Moths and their caterpillars can be important components of a garden’s biodiversity, providing food for predatory species such as birds and bats.
It often seems that moths are the poor cousins of butterflies when it comes to appealing to gardeners. However, with around 2,500 species in the UK, moths are hugely important for the food chain; some make good plant pollinators and are fascinating to watch in themselves.
Place in the food chain
Most adult moths are active at night, making them a key food source for bats and nocturnal web-building spiders. Owls and small mammals take moths, as do many common garden birds if they discover them in the day.
Moth caterpillars are less mobile and easier for predators to catch than adults. Insect-eating birds, such as bluetits, great tits and robins, need a regular supply of moth and butterfly caterpillars to raise their broods successfully.
Many species of parasitic wasps and flies develop inside the caterpillars, pupae and eggs of moths.
Attracting moths
Discover the wealth of moths in your garden by suspending a light over a white sheet on a warm night in summer. A good field guide will be needed to identify moths, but some are readily recognisable such as brimstone, mother of pearl, flame shoulder, yellow-tail, ruby tiger and blood-vein. By planting night-flowering, nectar-rich plants, which have specifically evolved to attract nocturnal insects, even more moths can be attracted to the garden. Nicotiana (tobacco plant) and Oenothera (evening primroses) are ideal. Summer-flowering jasmines, honeysuckles, Erica cinerea, Silene latifolia and sweet rocket are all valuable to moths.
Day-flying moths such as silver-Y moth and the impressive hummingbird hawk moth can be lured with sea lavender, buddleias, Centranthus rubra and Lychnis. Provide for their caterpillars by growing lady’s bedstraw, which is also food for the huge elephant hawk moth caterpillar (as are rose bay willowherb, clarkia and fuchsia).
Leave longer grasses, thistles and knapweeds in wilder parts of the garden; these are food plants for many smaller moths. Native hedging plants such as hawthorn and hornbeam support many moths, but so do introduced species such as buddleia. Gardeners reluctant to attract caterpillars that make holes in their plants should consider planting trees and large shrubs where the damage is easier to tolerate.