Many gardeners will shudder even at the idea of providing food for caterpillars. Too many cabbages, Brussels sprout and kale plants lost to the larval stage of the small and large white butterflies. It’s maybe not too surprising then, if we’re not all rushing to encourage those tubular eating machines into our patches.
But even the most hardened vegetable grower would (probably) consider planting some nectar rich flowers to attract the adult butterflies. They’re a delicate and colourful feature of warmer days in the garden. The hot summer of 2013 helped many British butterfly species to higher population numbers than had been seen for many years. Although the percentage increases in populations might sound impressive – small tortoiseshell numbers were up 200% on 2012, we have to remember that this was relative to populations that had been declining for many years. So, what can we do to help keep butterfly numbers heading in the right direction?
Yes, you guessed it – we need to grow not just lots of beautiful flowers to provide nectar for the butterflies, but also some of the plants that the caterpillars need to feed and grow… and there’s a whole range to choose from that goes way beyond cabbages and kale. For a start there are grasses – if you have space, leave a patch of grass to grow long and lush and you could be feeding the caterpillars of ringlet, meadow brown, gatekeeper and speckled wood butterflies.
If you want something more attractive and flowery than a patch of grass… primroses and cowslips are larval food plants for the Duke of Burgundy. This is a species whose distribution has become much more restricted since coppicing fell out of favour. While you might not get caterpillars, unless you’re lucky enough to live in the right part of the country… you will still get beautiful spring flowers.
Ivy is a really easy plant to grow. It doesn’t even need to take up much space in the garden – it will scramble up a tree, trellis or wall. Holly blue caterpillars will happily munch on ivy, as well as holly, brambles and dogwoods. And in return for a few nibbled leaves, you get to enjoy the lovely blue butterflies fluttering around the garden. Ivy comes into its own as a wildlife plant later in the year too – the late flowers are a brilliant source of nectar for insects still flying at the tail end of the season… there’s even a species of bee that times its life cycle so that it’s active when the ivy is flowering.
Depending on how you look at it, garlic mustard is either a weed or a wildflower. Either way, it is pretty – with small white flowers in late spring. The leaves are edible… no really, try them in a salad, they have a mild garlicky flavour. And if that’s not enough reason to let them grow, they also attract orange tip and green-veined white butterflies into the garden to lay their eggs.
And a final suggestion… nettles. Yes, I know that I keep going on about how wonderful nettles are – edible, full of vitamins and minerals, and a free food… you must all be growing them by now. But there’s more – they also feed the caterpillars of comma, peacock, red admiral and small tortoiseshell butterflies. Just think, a patch of nettles and a buddleja in the garden and you could be providing food for practically the whole life cycle.