Posted: 06/05/2013 at 20:22
I suspect your friend's friend is in a bit of a muddle. Do you mean named varieties when you say 'cultivar'?
Double flowers are not good for bees and butterflies. Nor are many foreign plants, but buddlias, heather and privet, brooms, ivy, clovers, obviously. Honeysuckle for moths. Do a bit of research on the internet and you'll find lots, I'm sure. Visit some gardens and see what's buzzing.
Remember bees and butterflies are more active in the sunshine.