I have 2 large salvia reglas. One is in severe stress and the other has some dye back. They were above 6 ft. and good and bushy. We had about 50 inches one year and the very next year we had 13 inches, and all of a sudden large branches started dying back. We are still in drought. This salvia is supposed to be very drought resistant. I have this theory that the very wet year rotted the roots , especially the deep roots, and then they didn't have the roots to feed the plant during the severe drought. I did start watering it, First time ever. I have stabilized the plant and cut off dead limbs. Now It is coming back green with a bit more die back on some limbs, not much. My question is , should I cut the plant back all over and make it grow back from low down, or should I just lop off the dead limbs and leave the healthy ones be.. If I do cut it back, How far should I cut it back,. The shape of this plant has gotten badly shaped. Usually I do not trim back the S. regla much at all because it is deciduous and not tender to the cold. I am frightened of putting the plant in more stress by over pruning.