A garden with butterflies drifting through it looks like a stroke of luck. In truth it is a plan. Because butterflies need two entirely different menus, and most gardens only cover one. The first is nectar for the adult butterflies, the one everyone thinks of. The second is caterpillar food for the offspring, and that one is almost always forgotten. A butterfly bush on its own does not make a butterfly garden. It feeds the guests, but it never lets them raise a family.
The good news: you don't have to dig up your garden. You just have to think about both menus and stagger the nectar so that something is always in bloom, from the first warm day in March to the last mild day in October. This article shows you how, plant by plant, month by month.
Why two menus, not one
A butterfly lives two lives. In the first it is a caterpillar and eats leaves, often only those of a single plant species. In the second it is a butterfly and drinks nectar, and here it is far less fussy. If you plant only nectar plants, you invite butterflies that hatched elsewhere to visit. As soon as they want to lay eggs, they move on, because the caterpillar food is missing. Your garden becomes a rest stop, not a home.
This is exactly the flaw in many so-called "bee-friendly" beds. They are filling stations, not nurseries. Anyone who truly wants butterflies in the garden, over years, with offspring of their own, has to think about the caterpillars' food plants too. And those rarely look like an ornamental bed. Their names are stinging nettle, wild carrot, alder buckthorn, or simply: meadow.
Nectar brings the guests in; the host plants keep them.
Gardener's rule of thumb
The first menu: caterpillar food
Start with the part almost everyone overlooks. Caterpillars are specialists. The swallowtail lays its eggs on umbellifers like wild carrot, fennel or dill. The brimstone needs alder buckthorn or common buckthorn, and nothing else. And the single most important food plant of all is the common stinging nettle.
On the nettle, the caterpillars of the peacock, small tortoiseshell, red admiral and map butterfly develop. Four of our most colourful and common butterflies depend on this one, often despised plant. The catch: the caterpillars only like nettles that grow in full sun and are young. A shady strip behind the compost heap is barely used.
Caterpillars live dangerously, and so they live in groups. The black-and-yellow caterpillars of the small tortoiseshell often sit by the dozen in a web at the tip of a nettle. It looks like an infestation, but it is exactly the picture you want to see. Don't pick them off, don't spray, just leave them be. In two to three weeks they will have turned into butterflies.
Alongside the nettle, other host plants are worth having, depending on which butterfly you want to support:
- Umbellifers for the swallowtailWild carrot, fennel and dill. Let a few dill plants in the herb bed go to flower instead of harvesting everything. The green-and-black ringed caterpillars are unmistakable.
- Buckthorns for the brimstoneA single alder buckthorn at the edge of a shrub border is enough. The brimstone is one of the first on the wing each year and overwinters as an adult in the leaf litter.
- Grasses for the brownsMeadow browns, gatekeepers and many blues need unmown wild grasses. A meadow corner cut only twice a year is their nursery.
- Bird's-foot trefoil and vetches for the bluesLegumes in the meadow carry the small blue butterflies. They need poor, unfertilised soil.
The second menu: staggered nectar
Now for the visible part. Butterflies need nectar from the first day of spring right into autumn, and without a gap. The most common mistake is a bed that explodes in June and stands empty by August. But that is exactly when, in high summer and early autumn, the most butterflies are flying. Think in four windows.
Spring · CW 10 to 17
The overwintered butterflies like the brimstone and the peacock wake early and hungry. Now every bloom counts. Willow catkins (goat willow), crocus, aubretia, grape hyacinth, wild fruit blossom and dandelion are the first lifeline. A flowering dandelion in the lawn is worth more in April than any ornamental perennial.
Early summer · CW 18 to 25
The bridge. Thyme, oregano, sage, cornflower, viper's bugloss and the first scabious carry the butterflies out of spring and into summer. Herbs you let flower are a double win here.
High summer · CW 26 to 34
The main flight period and the critical phase. Butterfly bush, hemp agrimony, scabious, globe thistle, betony and oregano provide the fuel for the second butterfly generation. Have a gap here and you lose the population.
Autumn · CW 35 to 43
The top-up for winter. Michaelmas aster, stonecrop, purpletop vervain and ivy blossom are the last nectar sources. Butterflies that overwinter as adults build up their fat reserves here. A late aster can decide whether they survive.
If you pick two to three plants from each of the four windows, you get an unbroken chain of nectar. More important than any single species is that something is always open.
The butterfly bush earns its name. No other shrub draws in so many butterflies in high summer. But it has two catches. First, it is pure nectar; no caterpillar eats its leaves, so it is only half the story. Second, it self-seeds strongly and is considered invasive in some places.
The native alternative for high summer carries almost as many butterflies and causes no problems:
Hemp agrimony is a native perennial that likes damp spots and forms a flat, pink flower head in high summer, on which butterflies sit as if on a landing pad. Together with scabious and globe thistle it is the backbone of a late nectar bed.
For autumn, the fourth window, the Michaelmas aster is almost unbeatable. It flowers when nearly everything else is already over.
What tells a good nectar plant from a hollow one
Not every bloom that looks lush actually gives nectar. Breeding for large, double flowers has bred the nectar out of many ornamentals. A double dahlia or a hybrid tea rose is often an empty prop to a butterfly: lots of petals, no access, no sugar. Stick to a few simple rules.
- Single over doubleChoose unfilled, open flowers. Where the butterfly can see the stamens, it can reach the nectar too. Avoid double cultivars.
- Native over exoticNative wild perennials and their butterflies have tuned themselves to each other over thousands of years. Exotic bedding plants are often pretty but empty.
- Plant in groupsPut in a small cluster of each species, not just a single plant. A patch of colour half a square metre across is found from the air; a lone flower is not.
- Sunny and shelteredButterflies are cold-blooded and love warm, windless spots. A sunny corner in front of a hedge or wall is visited far more than an exposed, draughty bed.
Structure and care: less is more
A butterfly garden thrives on not being tidied. The four most common mistakes are all well-meant order.
Mow in stages. If you have a meadow or a meadow corner, never mow it all at once. Always leave a third to a half standing, so caterpillars and pupae don't vanish with the cut. Twice a year, in June and September, in stages.
Leave the seed heads standing. Don't cut perennials back in autumn; wait until late winter, just before regrowth, around the end of February. Insects overwinter in hollow stems and seed heads. The spent hemp agrimony in January is not mess, it is a winter shelter.
Offer overwintering spots. Some butterflies, such as the peacock and the small tortoiseshell, overwinter as adults in wood piles, sheds or dense ivy. A deadwood corner or an old log stack is worth its weight in gold.
Provide damp spots. On hot days butterflies draw minerals from damp ground. A shallow dish of moist sand or a puddle in the bed that never fully dries out is a small, effective gesture.
One corner is enough to start
You don't have to overhaul the whole garden. Start with one sunny corner: a nettle patch, next to it a cluster of hemp agrimony or a butterfly bush, an unmown patch of grass, and a Michaelmas aster to finish. That is a complete, small butterfly world on a few square metres, with both menus. In the first year, guests arrive. From the second or third year, once the population has settled in, it becomes a home. The garden rewards patience, as always.
Häufige Fragen
Why don't any butterflies come to my garden even though I have lots of flowers?
You are probably missing one of the two menus. Many flower-rich gardens offer plenty of nectar for adult butterflies, but no caterpillar food for the offspring. Without host plants like nettle, wild carrot or alder buckthorn, the butterflies stay brief guests and move on to lay their eggs. Check as well whether your flowers actually carry nectar: double cultivars of dahlias, roses or chrysanthemums are often empty props to a butterfly. And look at the sequence of bloom; if nothing flowers in high summer and autumn, you are missing exactly the time when most butterflies are on the wing.
Which plants do butterfly caterpillars need as food?
It depends on the butterfly, because caterpillars are highly specialised. The most important food plant is the common stinging nettle: on it develop the peacock, small tortoiseshell, red admiral and map butterfly. The swallowtail needs umbellifers like wild carrot, fennel or dill. The brimstone caterpillar eats nothing but alder buckthorn and common buckthorn. Many small brown and blue butterflies need unmown wild grasses, bird's-foot trefoil and vetches. Important: the nettles have to grow in full sun and be young; shaded stands are barely used.
Is the butterfly bush good or bad for butterflies?
Both. The butterfly bush (Buddleja davidii) is one of the best nectar sources in high summer and rightly earns its name. But it is only half the story: no native caterpillar eats its leaves, so it feeds only the adult butterflies, not the offspring. It also self-seeds strongly and is considered invasive in many regions. Cut the spent panicles off consistently before they set seed, and always combine it with caterpillar host plants. Near nature reserves, plant the native hemp agrimony instead, which carries almost as many butterflies.
When should I cut back my butterfly garden?
Not in autumn, but in late winter, around the end of February, just before regrowth. Insects, and sometimes pupae, overwinter in hollow stems and seed heads. If you cut everything down and clear it away in October, you remove the overwintering shelters. Leave spent perennials like hemp agrimony and stonecrop standing over winter. Mow meadows in stages: only ever a part at a time, so caterpillars and pupae survive in the standing remainder.
How do I close the nectar gap in high summer?
The high-summer gap in July and August is the most dangerous, because that is when the most butterflies fly, yet many spring bloomers are already done. Plant late-flowering perennials deliberately: butterfly bush, hemp agrimony, scabious, globe thistle, oregano and betony carry through high summer. For the transition into autumn, Michaelmas aster, stonecrop and purpletop vervain follow, the last of which flowers into October. Choose two to three species from each time window and something is always open. And let culinary herbs like oregano and thyme flower; they fill the gap almost by themselves.
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