I will chime in here to agree that Amistad is an amazing salvia! Plus it naturalizes and survives hard freezes. I've lived in SC for 10 years and it seemed like I had a zone 8a microclimate but now after the last two winters I'd say we're more like 7b. So many of my salvias did not survive last winter. Amistad survived and grew into a 5 foot tall shrub covered with bright purple blooms!!
Also the coccinea salvias seem to reseed very well even if the roots do not make it thru winter. I have learned to collect the seeds from the coral variety that I grew from seed the last two years.
