Best Host Plants for Caterpillars

As temperatures start to rise, the life cycle of butterflies commences once more; eggs are laid, caterpillars emerge, food sources are desperately needed.

Mention the word caterpillar and most gardeners will shudder; they eat our plants, flowers and vegetables. In truth there are very few caterpillars that will munch their way through these, preferring instead the taste of wildflowers, native wild grasses and the leaves on trees.

It’s hard to leave a section of your garden unkempt, full of what in some cases can only be classed as weeds. However, if you can come to love a patch of rough terrain, you could so easily attract so many more butterflies to your garden, and we all love butterflies don’t we?

Top 10 food plants for caterpillars.

Here are our top 10 food plants for caterpillars, and which butterfly larva they play host to. The list is by no means exhaustive, but we hope that it will give you an idea of which plants more common butterflies like to lay their eggs on and the hatching caterpillars to then feed off. If you have any of these in your garden, or on your land, and can leave them to flourish, then you will be helping our butterfly population no end.

1. Thistles.

Seen as a somewhat invasive weed, throughout its life a thistle will play host to all sorts of wildlife. The caterpillars of the Painted Lady butterfly feed on their leaves. Birds such as goldfinch, greenfinch, siskin, linnet and redpoll all love to eat thistle seeds. They also use the thistledown to line their nests. Butterflies such as Peacock and Meadow Brown along with bees all feed on their nectar. We may see thistles as a prickly nuisance, but they are one almighty feeding station for our wildlife!

2. Nettles.

These are undoubtedly number one in the popularity stakes when it comes to caterpillars! Red Admiral, Painted Lady, Peacock, Comma and Small Tortoiseshell are but a few that will lay their eggs on nettles. The subsequent caterpillars then happy to gorge themselves on their leaves. As a child we learn to live in fear of these stinging plants, but leave a small patch alone (and be careful, they do spread like wildfire if left unchecked) and you will be rewarded with a multitude of butterflies once the caterpillars have pupated.

3. Birdsfoot trefoil .

Whilst one of its common names, Granny’s Toenails, may conjure up quite an image for us, the caterpillars of Common Blue, Silver Studded Blue and Clouded Yellow butterflies along with those of many moths such as the Six-Spot Burnet Moth love feeding on these bright yellow flowers.

4. Mixed grasses.

Many of us are happily planting wildflower patches in our gardens, but instead of wildflowers, how about an area of mixed native wild grasses? Native wild grasses play host to a multitude of caterpillars, both butterfly and moth. These include Large Skipper, Small Skipper, Marbled White, Gatekeeper, Grayling, Ringlet, and Meadow Brown. Aim for a mix of both coarse and fine wild grasses, and you’ll entice a greater range of butterflies to lay their eggs in your garden.

5. Alder buckthorn (Frangula alnus) and purging/common buckthorn (Rhamnus cathartica)

Caterpillars of the bright yellow Brimstone butterfly thrive on the leaves of buckthorn. It’s a shrub commonly found growing in scrub and woodland. Like the Thistle, Buckthorn is another great wildlife feeding station. Its leaves feeding the caterpillars of Brimstone Butterfly, its blossom providing nectar for bees and its berries food for birds during the autumn months.

6. Lady’s Smock or Cuckoo flower.

This pretty pale lilac wildflower is loved by the caterpillar of the Orange Tip butterfly. It flowers from April through to June on damp, wet grassland or by the side of ponds. You can read more about Lady’s Smock in our earlier blog.

7. Dog Violet.

The leaves of these low growing, pretty purple wildflowers are the host food for caterpillars of various Fritillary butterflies. Dog violets are common throughout France and the UK. They flower from April to June. Leave these in your garden and you’ll be helping to feed the caterpillars of the High Brown Fritillary, Silver-washed Fritillary, Dark Green Fritillary and so many more.

8. Salix caprea, common names: Goat Willow, Sallow or Pussy Willow.

If you have any Sallow in or near to your garden then you will hopefully attract the beautiful Purple Emperor butterfly. The Purple Emperor butterfly will lay a single egg on the upper side of a sallow leaf. When the larva hatches it will eat the sallow leaves until it is ready to pupate. The catkins of Salix caprea are also a mecca for early emerging butterflies and bees.

9. Wild Thyme.

I don’t know about you, but we have wild thyme spreading throughout our, as we lovingly like to call it, ‘weed lawn.’ Wild thyme plays host to the caterpillar of the somewhat scarce Large Blue butterfly. Greatly believed to still be in decline, the larvae of the Large Blue butterfly initially feed on the flower heads of wild thyme. If leaving wild thyme growing through our grass means we can help a beautiful, struggling butterfly such as this, then we’re more than happy to have a ‘weed lawn’ rather than a perfectly manicured bowling green!

10. Nasturtium.

The last plant on our list is an exception. It’s not a wildflower but a plant easily grown from seed or bought at the garden centre. For anyone with a vegetable plot, this is one of the most important flowers we can plant. It will help prevent cabbages from being decimated by the caterpillar of the small and large Cabbage White butterfly! Cabbage Whites love Nasturtium. Plant them next to your Brassica as a sacrificial plant, and these will help to save your vegetables, whilst still feeding the caterpillars. Alternatively, if you’re anything like me, and each year you end up with too many broccoli and cabbage seedlings, rather than throwing them on the compost heap, how about planting them in a different area of your garden, and allowing the Cabbage Whites to enjoy them!

Don’t be afraid of caterpillars

With the spread of pine processionary caterpillars, particularly throughout France, caterpillars have recently received quite a bit of bad press. Whilst these particular caterpillars can be quite harmful to trees, humans and animals, we shouldn’t let these make us afraid of other, harmless caterpillars. Caterpillars come in all sorts of sizes. Some are furry, others are smooth, but ultimately they all turn into either beautiful butterflies or moths which help to pollinate our plants, flowers and vegetables.

A few years ago we came across this rather large caterpillar in our garden, he’s the caterpillar of the Elephant Hawkmoth, measuring about 75mm in length. Was he large? Yes! Was he scary? No!

Without caterpillars we would not have butterflies. With wildflower and wild grass meadows vanishing, they need our help. Please try to learn to love a bit of rough, unkempt ground full of wildflowers and weeds.

If you have left a wild patch in your garden to help feed caterpillars we’d love to know, please do leave your comments in the box below.

Once you have perfected your caterpillar garden, you’ll then need to include plants to help the butterflies. In our earlier blog How to create a butterfly friendly garden you’ll find our suggestions for the best plants to include to provide butterflies with nectar throughout the seasons.

A bientôt

Katherine x

Help the butterflies and moths in your garden by providing them with a shelter.