Salvia stems are coated with white powdery stuff. Is it sick?
I have two large salvias. (probably garden sage) which were full and beautiful. I bought them already fully grown about 2 years ago. Although there is new growth around the base, and growth at the top, the long stems are totally bare and covered with soft white fuzzy stuff. The stems are very woody and brittle.
Question#1: Is this the characteristic of the plant?
At first I thought it was 'whitefly' and attempted to remove the coating with dishwashing liquid, vinegar and water. Then I applied NEEM oil. As soon as the stems were dry the fuzz was back. I don't think it's whitefly. Could it be something else?
#3: Are Salvia's prone to any paticular diseases?
#4: I wish to cut them back,HARD?
Any advice would be hugely appreciated!