Hi Bill...I think it depends on what kind of Salvia. Some are shrubby and others herbaceous. I only have the herbaceous kind, which are not reliably herbaceous here on the East Coast of Scotland. The shrubby ones cannot cope with the winds here as their stems are very brittle. Last year I planted Salvia nemorosa 'Caradonna' but so far I can't see any new growth coming from the base. So I would say they are not perennial in Scotland. But if yours is a nemerosa then it would be safe to cut off the old stems. If its a shrubby one, perhaps wait a couple more weeks to see if any more buds break further up the 'branches'.

I have several of the shrubby ones - the old wood can be cut back . . . just above a bud if possible . . . leaving 6" to 8" of growth. They will become much more bushy that way.

Normally I get plants with a label. It could be a meadow or woodland sage. They came as a potted display with annual begonias. Don't ask!! It just kinda worked. Last year they were with primroses.

I'd wait a little longer as they are forecasting wintry showers this week.