Salvias - tender perennials

I have just started to take an interest in salvias. Many are tender perennials such as Salvia guaranitica and S. darcyi and the books recommend that you protect them over winter. But there are other tender perennials such as S. patens, S. coccinea and S. splendens, where you are recommended to grow them as annuals. Does anyone know why there should be differant treatments. If you keep the 'annual' types over winter are they not as good as new ones grown from seed.

Although many are not that hardy, they include some lovely plants that flower for a long time. My S. microphylla was in full flower for 20 weeks and S. 'Mystic Spires' for 14 weeks. Both were in partial flower for even longer.

 

I had a passing interest in salvias for a while Peter.
I remember growing coccinea, splendens and patens all as half hardy bedding plants.
The others, I didnt touch on, but I did grow some types that were shrubby by nature to which the ones you mension may well belong.
I think its patens that can be lifted like dhalias and replanted the next year, which I have done with no real benefit. Its easier from seed.
Presumably the "shrubby" ones are the ones that wont flower the first year from seed.

 

Pete, thank you for your comments. I have been thinking about this and I believe that you have put your finger on it. All the Salvias I mentioned are half hardy. It is logical that the ones that will grow to virtually full size and flower well in the first year are usually grown as annuals - it saves overwintering them. But I suspect that the others don't reach full size and flower in the first year, consequently you have to overwinter them.

I have a S. patens overwintering in its original pot in a summerhouse. I was aware that you could just store the tuber, and I am dying to dig it up just to see what the tuber looks like. I believe there are several other Salvias that make tubers. In fact there must be a variety of plants that do. I am overwintering some Verbena rigida is pots. When I dug them up they had long thinish tuberous roots, which I understand you can also treat like Dahlias.