Q. My problem is my 20-year-old rosemary. It has grown very large, nearly 7 feet across and 4 feet tall, and every year it preforms like a champion, until this year. I knew that the summer and winter had been stingy with natural water, so I was careful to add some supplemental watering when it wasn’t too cold. As spring came on, I noted that a number of rosemary bushes around town were either completely dead or mostly so. In my case half of my rosemary was/is dead and the rest was/is coming back but with dead areas. I’m wondering if it’s been the overly dry weather, age (after all, it’s nearly 20 years old) or another cause that caused this, and if it’s too late to try to save my…