A gardener's guide to butterfly-friendly plants
Three quarters of butterfly species are in decline in the UK, but gardeners can play a key role in providing colourful visitors with much-needed habitats.
Even small gardens in built-up areas can support a great variety of butterflies if they contain the right plants. In the heart of London, the Museum's Wildlife Garden has recorded 23 species of butterfly and many more moths.
Butterfly expert Luke Brown explains which flowers from around the world you can plant to encourage butterflies, and Wildlife Garden Manager Caroline Ware reveals how a variety of British native plant species can also encourage butterflies and moths in gardens.
A buddleia is also called a butterfly bush, and for good reason: its rich supply of nectar attracts a wide range of native British butterfly species.
The blooms peak in August and do best when planted in a sunny or partially shaded area in a garden.
Luke says, 'Many traditional gardeners will want to stick with native species, but there some amazing flowers and plants from around the world that attract British butterflies that I use in my own garden.
'Buddleias are one of the best nectar sources for our butterflies that you can plant. There are smaller varieties such as buddleia buzz that are more suitable for smaller gardens.
'It's important to prune buddleias in spring. I cut back mine in March to keep them growing well.'
The common lilac (Syringa vulgaris) is a medium-sized deciduous shrub that can be planted in spring or autumn, and provides a rich source of nectar for butterflies when it blooms in May and June.
Lilacs need a lot of sun and good drainage to bloom well, so choose a south-, west- or east-facing site that offers plenty of light and not too much water.
Deadheading the flowers regularly is also good for butterflies.
Luke says, 'Deadheading helps produce more flowers and nectar for butterflies to feed on.
'In the Sensational Butterflies exhibition at the Museum we can spend up to three hours each day deadheading and tending flowers so that they produce as much nectar as possible. The same principle applies to attracting butterflies in outdoor gardens.'
English Lavender (Lavendula angustifolia) is a fragrant shrub, best planted in the spring once the weather has begun to warm.
Lavender blooms throughout the summer and is a food source for a variety of British butterflies during these months.
Just like the lilac plants, lavender thrives in full sun and well-drained soils and does particularly well in chalky, alkaline soils.
Keeping garden flowers well-watered helps the plants to produce more nectar for butterflies and other pollinators.
Common honeysuckle (Lonicera periclymenum) is a deciduous climber that flowers during the summer months.
The honeysuckle does well in a wide range of aspects and soils, either in full sun or partial shade.
Wildlife Garden Manager Caroline says, 'Honeysuckle is great for attracting butterflies, but it also offers a great nectar source for moths, which are attracted by the powerful scent of the flowers in the evening.'
It's not necessary to prune honeysuckle, and it is an ideal plant for wildlife gardens, but the plant can be pruned in winter if it's taking up too much space in the garden.
Stinging nettles (Urtica dioica) don't always have the best reputation among gardeners, but they are a crucial part of the ecosystem for many British butterfly caterpillars.
Luke says, 'Host plants for caterpillars are essential to promote butterflies in your garden. Adult butterflies generally feed from the nectars of flowers, but caterpillars don't necessarily benefit from those plants, and often favour other host plants.
'Stinging nettles are one of the most important plants in terms of the percentage of British butterfly caterpillars that will feed on them. There is also a non-stinging variety for gardens where small children play.
'Nettles are the food plant for the caterpillars of red admiral, small tortoise shell, painted lady and comma butterflies.
'It's important to treat your nettles like any other garden plant if you are growing for the benefit of butterflies. Cut them regularly to get good fresh growth from the nettles.'
Leaving a wilder of area of the garden, featuring long-growing grasses, also provides habitat for butterflies.
The Wildlife Garden contains small meadow areas, ideal habitat for certain British butterfly species providing both nectar plants, such as oxeye daisies and knapweed, and grasses including cock’s-foot and fescues for meadow brown, large, small and Essex skippers to lay their eggs on.
Caroline says, 'Speckled wood butterflies thrive in dappled shade and lay their eggs on woodland grasses such as false brome.'
Reserve a place where you can allow grass to grow long, and see which species come to visit.