My soil here is clay but I grow my Salvias in raised
beds so they drain well during some of our heavy downpours.
We can better answer your questions with some more info...
1)Do you know which Salvia you have?
I have about 8 different species that are red.
2)Is you plant in sun or shade?
I prune some of my plants twice a year then feed w/a slow
release organic fertilizer 6-12-6(No Salt). The potassium
helps in areas where it is tied up in the soil and unavailable to the plant.
3)What part of California?
Art