I have had a terrible time trying to get rosemary established in my herb garden. I've tried several different cultivars. I buy them as 4" pots, plant them out, and they do well during the first growing season. They also over-winter OK. Then, during spring clean-up, when I weed, prune and mulch everything, they all of a sudden just turn brown and die. Do they not like to be pruned? Allergic to mulch? What?? The last variety I chose specifically for the name - Hill Hardy. Previous fails have been Arp, Tuscan Blue, and Barbeque.