Moths: encouraging into your garden

Moths are often neglected or ignored in favour of their cousins the butterflies when considering which insects we want to encourage into our gardens. However, with around 2,500 species in the UK, moths can be extremely diverse and interesting. Moths are hugely important for the food chain and can provide pollination services, but there is increasing evidence that Britain’s moths are in decline.

Elephant Hawk Moth

Quick facts

Suitable for Encouraging moths into the garden
Timing Late spring to autumn
Difficulty Moderate

What moths are in your garden?

A good field guide will be needed to identify moths, but some are readily recognisable, such as brimstone moth, mother of pearl, flame shoulder, yellow-tail, ruby tiger and blood-vein. There is also a wealth of online identification assistance such as at the UKMoths website.

To observe some of the range of  moths in your garden, suspend a bright light over a white sheet on a warm night from spring to autumn.

You can also submit records of species you have seen to Butterfly Conservation's Moths Count scheme to contribute to knowledge and conservation of  moth species.

Moths in decline

Long term data from the Rothamsted Insect Survey has shown that two thirds of British larger moth species have declined in abundance since the late 1960s, and around 62 species have gone extinct. This data was gathered using a network of light traps throughout the UK, one of which is operated at RHS Garden Wisley.

Declines have also been seen in Northern Europe and may be occurring in the rest of the world. It is thought that habitat loss or fragmentation is one of the main drivers of these declines, such as changes in farming practices and increasing urbanisation. Moths are considered good indicators of environmental and land-use change, and as such these trends in moth populations add to the concerns over general biodiversity declines.

How to encourage moths

Many gardens are already good habitats for moths. By planting night-flowering, nectar-rich plants, which have specifically evolved to attract nocturnal insects, more moths can be attracted to the garden. Lists of plants that can attract a wide range of pollinators can be found at RHS Perfect for Pollinators.

  • Nicotiana (tobacco plant) and Oenothera (evening primroses) are ideal. Summer-flowering jasmines, honeysuckles, Erica cinerea, Silene latifolia and sweet rocket are all valuable nectar plants for moths
  • Day-flying moths, such as the silver-Y moth and the impressive hummingbird hawk moth, can be lured with sea lavender, buddleias, Centranthus rubra and Lychnis
  • Provide for moth caterpillars by growing lady’s bedstraw, foxglove, primrose and thyme. The elephant hawk-moth caterpillar, which turns into a large and colourful moth, also enjoys rose bay willowherb, clarkia and fuchsia
  • Leave longer grasses, thistles and knapweeds in wilder parts of the garden; these are food plants for many moths
  • Native trees and hedging plants, such as oak, birch, willows, hawthorn and hornbeam, support many moth caterpillars and many ornamental garden plants also provide feeding opportunities for caterpillars

Place in the food chain

  • Most adult moths are active at night, making them a key food source for bats, nocturnal web-building spiders and other nocturnal predators. Owls and small mammals take moths, as do many common garden birds if they discover them during the day
  • Moth caterpillars are less mobile and easier for predators to catch than adults. Blue tits, great tits, robins and many other birds, need a regular supply of caterpillars and other insects to raise their chicks successfully
  • Many species of parasitic wasps and flies develop inside the bodies of caterpillars, while others attack the pupal/chrysalis or egg stage in the life cycle of moths

Problems

The caterpillars of moths eat the foliage or other parts of plants. In gardens this can be to edible, ornamental plants or ‘weeds’. In many cases this damage consists of damage to leaves only and can be tolerated, as the damage often has a very limited effect plant vigour and appearance. Where possible the damage should be tolerated and growing healthy, large or more vigorous plants can make this more acceptable. If damage is considered unacceptable it may be due to only a few caterpillars, these can often be removed by hand, a night time search is more likely to reveal the culprits.

Many of the caterpillar pests are the larvae of moths, including; angle shades moth, codling moth, holm oak leaf-mining moths, horse chestnut leaf-mining moth, leek mothpea moth, plum moth, winter moth and tortrix moths. Cabbage caterpillars may be those of moths or, more commonly, butterflies.

Advertise here

Gardeners' calendar

Advice from the RHS

Find out what to do this month with our gardeners' calendar

Advice from the RHS

Did you find the advice you needed?

RHS members can get exclusive individual advice from the RHS Gardening Advice team.

Join the RHS now

Discuss this

for the site or to share your experiences on this topic and seek advice from our community of gardeners.