I agree with Brigit the Irish Gal. I planted rosemary in 2011 and it is still going strong. In Zone 6, where I live in Southeastern PA, rosemary and several other herbs are perennials. Not all of them, but rosemary, thyme, and sage are perennials in this Zone. If the plant gets too large, either use it up in cooking, dry it and place in jars, use it for aromatherapy, add a sprig to a bouquet, or divide the plant and move it to another location. You can create a rosemary hedge or a border for another part of the garden. Rosemary is a repellant to rabbits and deers and to some insects.