Sedums, Sempervivums. some of the more compact Delospermas, Phlox subulata, Mt. Atlas Daisy. Clumping Gazanias might work, if the winters are mild enough. Probably many others that wouldn't grow in my climate. Probably some more that do, but I don't know to recommend because I don't know your climate--or plant import laws.

Thanks for the advice. I'm on the French / Swiss border, 15 mins from Geneva. The summers are typically 3 degrees warmer than the UK. Close to the Alps and Jura mountains and at 400 metres above sea level, the winters can be harsh (although no worse than the UK last winter) and snow is almost guaranteed. The garden centres are relatively good with a variable choice

Apologies, I have just read your profile.

I lived for one year in Michigan which is relatively comparable on the climate. Nice warm summers, up to 100 degrees (but not the humidity) and down to 0 degrees F in the winter

Ah, well! A lot of the things that I would grow wouldn't take Michigan-style winters. You might want to check with The Arboretum at Flagstaff (www.thearb.org) Sauverny. They have been testing hundreds of plants in the cold winter, hot summer northern Arizona climate for close to a decade, now.