Stachys byzantina, Heuchera 'Obsidian', Lavandula x intermedia and Euphorbia amygdaloides make a border which looks good year round at the edge of the lawn above the pool, the purple of the Heuchera making the silver Stachys sing. The Stachys is a fabulous plant for the climate in this part of France, never getting that bedraggled look it seems to have all winter in London!