I used to buy Rue at nurseries and inevitably they'd die within a couple of years. Then I got several in trade from a butterfly person in South Texas and have had Rue since then. I'm leary of pruning it much, however...I lost the last one I pruned quite a bit. Fortunately I had two more bushes and I have had volunteers come up from time to time. Large rues like mine can bloom almost year-round and it's an excellent nectar plant...not to mention a butterfly host plant for both Black Swallowtail and Giant Swallowtail. These are Red Admirals nectaring on a Rue bush.
