@beryl I love to see them too. It's amazing how they seem to prefer the white buddleia to anything else which is why we have 4 white ones in the garden.
@susiemc I used to have a white one but I do not know what happened to it !! but last year I bought a variegated leafed one with dark purple flower --I have not found as many butterflies on this one as the light lilac coloured one !! I wonder why !!