Could it be mildew from too much rain? There might be a spray for it unless you have hummers and don't want to use it.

Looks like powdery mildew. Farinaceas are prone to it. I tossed all of mine because of it. My Columbines have a tendency for it also. There are fungicides that are not harmful to use in the garden. Safer makes one, also I believe you can use Neem oil or make a spray of milk water. Once it gets a good hold it is VERY difficult to get rid of. You can also cut it all the way back and start over if the wetness is gone. Do not water these over head and esp. not in the evening.

Oh yeah, been there done that with this particular salvia, i think its the Victoria Blue Queen or something. Yeah, drove me nuts. I dont plant it anymore, as much as I would like to.

Thanks, I removed it.