I'm no expert, but I hate to see a first post go unanswered-- and your first experience turn out to be a bad one. Hopefully someone who knows more about salvia will chime in.
I don't know the exact problem, but since these are new plants that you've transplanted, I'd suspect the underlying problem is stress. "Stress" isn't going to cause the leave to blacken, but when stressed, plants become susceptible to a host of other problems that they could normally overcome. Transplanting stresses plants, changing environments does, too.
My recommendation would be this. Get them out of the direct sunlight for now. Put them in a bright space, but one that doesn't get full-on sun all day long. If you can choose, someplace that gets morning sun, and then afternoon shade, would be better than the opposite.
You are probably over-watering them. Be sure the pots have drainage holes. Stop watering them every day, but rather, water when needed. My recollection is that salvia can handle being a bit dried out (but maybe the experts will say otherwise). Let them dry out a bit, then water when you stick your finger into the soil about an inch, and it feels dry. If you have the pots in saucers (underneath) be sure the saucers are not filled with water.
If-- and hopefully when-- they seem to perk up, move them gradually into full sun. Take, maybe 3-4 days to do this. Gives them a chance to physiologically adapt to their preferred environment.
This is the best I can come up with. Hopefully someone will have other ideas for you!
Good luck!!
Last edited by Marica; May 27th, 2009 at 02:02 PM. Reason: add'l info
"No crime is involved in plagiarizing nature's ways" (Edward H. Faulkner, 1943, "Plowman's Folly," University of Oklahoma Press).