Most of us start with the same plant: a buddleja, bought in a fit of enthusiasm, plonked in the sunniest corner and hoped over. It works, for a fortnight. Then the flowers fade and the butterflies move on, because a border that feeds only adults is only half a habitat. The trick is to think about the whole life cycle. Adult butterflies and moths need nectar to fuel flight, mating and egg-laying. Their caterpillars need leaves — very specific leaves, usually from native plants. Give them both in one border and you turn a passing visit into a resident population.
The good news is that a butterfly border is one of the loveliest things you can plant. It is colourful, low-effort once established, and it hums from June to October.
Picture your border as a restaurant with two menus. The nectar menu serves adults: single, open flowers where a butterfly can reach the nectar with its long tongue. Doubles and heavily ruffled varieties often have little or no nectar, which is why a blowsy old-fashioned shrub rose is far less useful than a simple daisy.
The leaf menu serves caterpillars, and it is where most gardens fall down. Our native butterflies and moths evolved alongside our native plants, so they are fussy. A holly blue will not lay on a buddleja. A brimstone will not lay on a rose. If you want the next generation, you need to plant the right leaves — and be willing to let something eat them.
Plant in generous drifts of three to five of each variety rather than one of everything. Butterflies are short-sighted and follow colour in patches; a single lonely verbena gets overlooked.
Aim for something in flower from April to October and you will never have a hungry fortnight. Choose single-flowered forms, and favour open daisy shapes over trumpet shapes.
This is the part that turns a pretty border into a conservation project. Tuck a few larval food plants into the back or along a boundary where a little chewing will not upset you.
If you have room for only one, make it nettles. If you have room for two, add garlic mustard.
Butterflies are cold-blooded. They need warmth and they hate wind. A south or south-west facing border with at least six hours of direct sun is ideal, and a low hedge, fence or wall behind it creates a suntrap where they can bask. Leave a bare patch of earth or a flat stone for basking — you will often spot a peacock or small tortoiseshell warming up on it first thing.
Most nectar plants prefer poor-to-moderate soil and resent rich feeding, which produces floppy leaves and fewer flowers. Resist the urge to mulch heavily and never use insecticides or weedkillers anywhere near the border. A bug spray cannot tell a cabbage white from a ladybird, and it will wipe out your caterpillars along with the aphids.
The kindest approach is a slightly untidy one. Leave seed heads standing through winter — they feed birds and shelter overwintering caterpillars and pupae. Don't cut everything back until March, and when you do, leave the cuttings in a corner for a few days so anything hiding inside can crawl out.
Deadhead spent blooms to keep flowers coming, but leave a few to set seed. Allow leaf litter to gather under shrubs rather than sweeping it away. Water new plantings well in their first summer, then let them fend for themselves.
Do all this and by next July your border will be doing two jobs at once: feeding the adults you can see, and quietly raising the ones you can't.
Tawny Refuge shares practical, down-to-earth guidance on british wildlife gardening and backyard conservation for readers across the UK.
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