In addition to your need for plants that will grow well in areas with mild winters, you also need to consider the hot summers and extensive rainfall in your area. Shop local nurseries. When you see a plant that you like growing in someone's yard, ask about it. If it is growing well for them, it should grow well for you. Also visit local botanical gardens, and consider making a trip to Baton Rouge, which has several excellent destinations for garden tourists. Also check with your local cooperative extension service for recommendations of perennials that grow well in your area.