I have been trying to grow Salvia semiatrata for many years and I can say it is one of the most difficult salvias for me. I can grow other species, which I think are realted, (S. lasiantha, S. variana, S. aspera) but semiatrata seems to be even more difficult than S. aspera. I have read it is a plant of xeric places, growing in cliffs among cacti and succulents. I have seen pictures of spectacular specimens growing in Australia, California and France. I live in Zone 9, by the coast. 900 mm annual average rainfall. Any advice would be very welcome.