how to create a butterfly garden
Walking through the hay meadows in Transylvania last summer felt like a visit to a perfect place, not just for the wildflowers – the salvias, aquilegias and orchids – but for the butterflies you kick up with every step. It’s not, I have to admit, quite as miraculous as the story a friend of mine told me about driving along the road in Bhutan. There, the butterflies were so thick he had to use the windscreen wipers to see where he was going, but in the Transylvanian mountain meadows there is a frothy, dancing upper-storey to the long grass, extending it into a third dimension, flecks of colour moving continually a few feet in the air.
The grass is also alive with caterpillars. I sat in one place and counted how many I could reach in the circle around me. There were 13; brown and black-spotted hairy ones, some shiny green and some grey with yellow flecks.
It was a whole new world I’d hardly thought of before that day, but it gave me a new resolution, not just to learn all our native butterflies, but what their caterpillars look like and feed on. The safest time to sow wildflowers and plant shrubs is in the next couple of months. The shrubs will have time to get their roots well established without the need for watering and many wildflowers need cold to encourage germination. Sow now and you’ll have the best results.
The hay meadows around us in East Sussex have had most of their wildflowers stripped from them by the widespread use of nitrogen fertiliser over decades.
This boosts the grass, which in turn out-competes the wildflowers, but they are still full of wild sorrel, so thick that the grass turns rusty red in May and June, with the more delicate, but dock-like flowers mixed in with buttercups.
Sorrel is the food plant of the small copper butterfly, which flutter up when you walk through the meadows before they’re cut. If you don’t already have plenty of sorrel surrounding you, this is a quick and easy plant to grow. Sow it from February and it germinates well and you’ll soon find small coppers landing on the leaves and laying their eggs. You can grow the wild form, Rumex acetosa, which is edible, with a tangy lemon flavour (a few leaves transform a salad), but the larger-leaved, French domestic sorrel will give us – and the small coppers – a bigger meal.
Bird’s-foot trefoil is another widespread and easy-to-grow wildflower. It’s the main food plant of the common blue, a native butterfly, which is really struggling. Bird’s-foot trefoil has pretty, pea-like flowers and creeps along, forming a golden-yellow carpet an inch above the ground. It makes a good addition to any area of unmown grass. More of us should try to grow it.
In a damp spot around a pond, you could introduce cuckoo flower, also known as lady’s smock, which turns ditches in my locality pinky-mauve in the spring.
This is a key plant for the orange-tip butterfly, which you should see in abundance as soon as the flowers emerge. The adult females are drawn in by the soft scent and they lay their eggs on the flower heads. Once hatched, the caterpillars eat the seedpods, munching their way down the stem.
As well as these colourful flowers in your lawn edges, in certain areas it’s good to let the grass grow longer. Then you’ll get a whole host of different butterfly visitors, there to lay their eggs. You may draw in meadow browns, gatekeepers, ringlets, small and large skippers, speckled woods and wall browns. All their caterpillars feed on grass – on timothy and the fescues in particular – so with no extra planting, you can increase your butterfly count many times.
Fill out hedges
There are many plants we can add to our hedges, filling out the odd gap here and there. Buckthorn is a key plant for the brimstone butterfly and is easy to add to a hedge. The brimstone female can smell a buckthorn plant five miles away; plant one and you should get brimstones in your garden.
Many of us already have holly and ivy in the hedge, food plants for the holly blue, but this also breeds on dogwoods and escallonia, so it’s good to slot one or other of those in. And if your garden is close to old woodland, grow wild honeysuckle, the food plant for white admirals. This is not a likely garden visitor, but gardens next to rich woodland could lure it in. Then there are hops, hazel, willow and currants for the comma. This was very rare in the early 1900s. No one knows why it’s doing so well now, but it’s on the increase.
In wilder areas of garden, we have in the past been encouraged to allow nettles to run riot. Nettles are the food plants of the peacock, small tortoiseshell, comma, red admiral and painted lady. All these insects do use nettle – almost exclusively – but they need large stands in full sunlight. The Sheffield BUGS project put big tubs in about 60 gardens over three years, and not one of the basic target butterflies used any of the tubs – with the exception of one stray comma caterpillar which had probably come in from currants, willows or hops nearby. This result was so marked, and so contrary to established dogma, that Ken Thompson called his brilliantly useful book on gardening for pollinators No Nettles Required. If you grow other food plants there’s no need to feel guilty about nettles.
In the borders
Away from the wilder areas and into the garden proper, sweet rocket (Hesperis matronalis) is a must-have plant for butterflies. This will draw in the small white and the green-veined white, as well as the orange tip, which compete for its seedpods as their caterpillar feeding ground. Sweet rocket is a wonder-plant. It makes a great cut flower, has a sweet, soft scent and grows well in sun or shade, so we can all happily introduce this to our gardens for next summer.
Then there’s the classic veg garden enemy – the large white butterfly (the biggest of the “cabbage whites”) – which is in now in major decline. We veg gardeners tend to hate it and give it a regular dose of pesticide to keep its numbers down, but if we continue, even this will become a rarity. We would all mourn its disappearance.
Instead, let’s try to welcome it and sow lots of nasturtiums as a sacrificial crop. The large whites particularly go for the tall climbing nasturtiums such as the Alaska Series, but I found they happily munched away at 'Black Velvet’ and my new-found favourite nasturtium, 'Cherry Rose’. If you find a caterpillar on your cabbages, don’t squash it – as I have to admit I used to do – move it to the nasturtiums and allow it to happily feast away.
Over the winter, think how to plant more butterfly food plants in your own garden and cram in more nectar-rich flowering plants in the spring. Then you’ll have the pleasure of doing that traditional thing with your children or grandchildren: pack a large jam jar with nettles, topped off with a pair of old tights. Enclose a few peacock caterpillars (which you should find on a good patch of nettles) and feed them fresh nettles every day. Watch closely over the course of a few days until the caterpillars turn into pupae, and then hatch into miraculously beautiful things. You can then release them into the garden to start the cycle again.
This article first appeared in The Telegraph on 30th December 2013.