About 9 months ago my wife and I went walking here in Brazil and saw some very pretty red salvia growing by the roadside. We took some seeds and planted the seedlings out in a border. I discovered this salvia is known as Texas salvia (Salvia coccinea). Do any of you guys have it? It's kind of a weed out here but very pretty. My question is: What do you do with the plants after they flower? My gardening book says it is perennial but to me it looks like an annual. Is it worth pruning it back? If so how much? In our more fertile garden soil it has grown to quite a size. I noticed it has already self seeded.