Creating a butterfly habitat-ish(?)

CLB

This could be a long one, so grab a cuppa if you want to read it! 

From last years experience, caterpillars LOVE nasturtiums. (If you know of any other EASY to grow plants like these then let me know!)  So this year I'm going to plant more Nast. so there will hopefully be more caterpillars/food for them. 

I've recently seen someone post a picture (on reddit) of their soon to be butterflies that they've helped overwinter, I'm guessing by keeping them in a cool spot? (Maybe in a container in the shed? There was no context in their post) 

So I'm wondering if anyone has done that here in the UK, and how you suggest trying to help these little caterpillar friends out, or if you suggest I just leave them be in the garden? My 1st thought was to get a small greenhouse and if possible add a mesh lining (assuming it's not already mesh) for the caterpillars to cling on to so they can pupate. And I can grow the Nast. Outside and bring them in when the eggs have been laid, or grow them inside the greenhouse and the butterflies will find their way in? 

If anyone has experience with raising butterflies or at least helping them in any way you can, please let me know! Also I understand not all butterflies are as they seem, some are moths, but I dont mind, I just like see all the caterpillars and butterflies in my garden! 

Thanks for reading (if anyone actually managed to without getting bored!)

Fran IOM

@CLB I am just bumping up your thread as you didn't receive a reply. I don't know if any other posters have done what you would like to do but you never know. 

Elothir

Can't really help too much personally as I've never done anything with Caterpillars.

However it's worth bearing in mind that each species of Caterpillar will more or less only eat from a handful of plants, so if you frequently see particular Caterpillars and/or Butterflies and identify them you might get a better idea of what plants will best support them.

This site seems to have a fairly in-depth guide to them (linked to the Nasturtium since you mention them): 
https://www.ukbutterflies.co.uk/foodplants.php#Nasturtium

So if you work out what ones you're seeing, you could see if any of their other food plants take your fancy. They also have some recommended nectar sources for the adults, though I would imagine that so long as a plant provides plenty of easily accessible nectar it should do the trick?

Skylarks

No experience but have found this which may give you a starting point 
https://www.rspb.org.uk/get-involved/activities/give-nature-a-home-in-your-garden/garden-activities/growfoodthatcaterpillarslove/

I’m a terrible gardener, especially when it comes to weeding. I often see Cinnabar caterpillars and moths in my garden due the the ragwort weeds that grow in my garden. 

Edit - sorry don’t think it is ragwort weed now I’ve googled a photo but another weed.

robairdmacraignil

The cabbage white butterfly looks for cabbage family/brassicas to feed its caterpillars but have not tried to encourage them myself. I have seen nasturtiums do provide good food fro them and they are fast enough growing that it does not set them back too much. Also seen lots of caterpillars eating leaves on my Persian ironwood tree and on oak tree leaves. Fort the butterflies the butterfly bush/buddleia is great to attract them and I have seen them to also stop on erysimum Bowles Mauve and red valerian seems particularly attractive to hummingbird hawk moths.

Bijdezee

I dont know if this is helpful but I have found that the carrot family of plants Inc dill etc attract a lot of butterfly eggs and caterpillars. We had swallowtail on them and managed to overwinter a pupa. 
Good Luck with it all, sounds very interesting. 

Singing Gardener

I think the caterpillars you get on nasturtiums are large whites and small whites (both of which are popularly called cabbage whites). They overwinter as pupae but I should think they would be best left where they are as they don't need protection over the winter.

Some British butterflies, such as peacocks and tortoiseshells, overwinter as adults and they do need some protection from the cold. They often find their way into sheds and outhouses and will also overwinter in hollow trees etc.

@Bijdezee, I envy you having swallowtails. We don't get them in Essex - I think they are only in Norfolk in the UK. When I was a teenager I used to breed them as well as other types of butterflies and moths.

Rob Lockwood

Yep, from a little reading the food plants of caterpillars vary by species; I'm looking at finding a space for some nettles as most of the more interesting butterflies I remember from childhood lay eggs solely on them.  I can't imagine the caterpillars need much help to find a place to pupate, so find the butterflies/moths you like, plant accordingly and nature should do the rest!

Hippophae

Hi CLB. Great topic for a thread! Something I am very into myself. I’ve recently started acquiring and planting butterfly or rather caterpillar host plants. So far I’ve bought a buckthorn (Rhamnus cathartica) for the caterpillars of the Brimstone butterfly which I often see zooming around the garden. Also bought a hop plant (Humulus lupulus) at a garden centre down in Kent a few weeks ago before the lockdown started. I believe this will offer food for the larvae of Comma, Peacock and Red admiral butterflies. Then I simply had to get hold of some cuckoo flower (Cardamine pratensis) not just for the orange tips but also because it happens to be one of my own personal favourite British native wildflowers! There are a few native plants like bird’s foot trefoil and some native wild grasses growing in the meadow with also serve as host plants to some of the less familiar butterfly species. 

All in all hoping for this summer to be a lepidopterist’s dream in the garden.
Please keep us updated on how your butterfly gardening grows! 🦋