Sage (Salvia nemorosa 'Caradonna') sure is a beauty! I googled and found this page: http://www.gpnmag.com/article/... and near the bottom under Availability it says Cardonna has just been introduced to the market and may be difficult to find but it lists a couple of places that may carry it.
Hopefully other members who grow this lovely Salvia will be along soon to offer suggestions.
~ I'm an old gal who still loves playing in the dirt!
~ Playing in the dirt is my therapy ... and I'm in therapy a lot!