Garlic Mustard Alliaria petiolata is a widespread, rather pungent plant of hedgerows, roadside verges and woodland rides and one that many naturalists pass by without a second glance. But it is always worth close inspection, being an important larval foodplant for two attractive butterflies – the Orange-tip and the spring generation caterpillars of the Green-veined White. So when you pass a patch pause for a moment, and see if you can spot any eggs, larvae or pupae.
Above: Garlic Mustard growing on a roadside verge. Paul Sterry/Nature Photographers Ltd
Above: Orange-tip caterpillar (left) and pupa (right), the latter attached to the stem of Garlic Mustard. Paul Sterry/Nature Photographers Ltd
Above: Green-veined White caterpillar (left) and pupa (right), the latter attached low down on a Garlic Mustard stem. Paul Sterry/Nature Photographers Ltd
In flowering terms Garlic Mustard is a bit past its best just at the moment, its blooms replaced by seedheads that are elongating and maturing day by day. Unfortunately this is also the time of year when highway verge-cutters and tidy-minded gardeners turn their attentions to verges and borders. So if you have any influence over things try to encourage people to spare a thought for Garlic Mustard and its dependent butterflies. The more patches of this plant that can be spared, even when it dies back to dry stems in autumn, the better it will be for Orange-tips and Green-veined Whites. Cut back the plant in its prime and there’s every chance you will kill off the next the next generation of these attractive butterflies.