I think this is a Large White, if it isn't then it's certainly a Small White! A Cabbage butterfly in any case. The identification sites are confusing: males have one spot/no spots, females have two spots/one spot, the grey on the wings is horizontal/vertical...and so on. I think maybe there are lots of variants, and we'll leave it at that!
I haven't seen many butterflies here this year, even considering there haven't been a lot in previous years. I get thousands of bees but obviously don't grow the kind of plants butterflies favour, though they do like the phlox that are flowering at the moment. Funnily enough, I just glanced out of the kitchen window and there was a pair of Whites dancing about.
I need to get some more butterfly attracting plants, I'm not bothered about the inevitable caterpillars as the birds will just have more to feast on. Buddleia is an obvious one, verbena as well. I have sedums, honeysuckle and lavender which they also like. Purple seems to be a common theme when I look on gardening websites...I wonder if this is a coincidence?
If anyone has any particular recommendations please let me know. Remember, though, that it must be very hardy and frost tolerant to survive here.