Plants in pots tend to dry out very quickly, way faster than plants in the ground. So they need watered regularly or they will dry out. Now if they were in the ground, they would not need watered as often. What you have is a perennial -a plant that returns every year. They usually die down in the winter (dormant) and then re-sprout when the weather warms in the spring. The flowers that actually do die, and have to be replanted every year are called annuals. Those are mostly the little colored flowers you see in the 6 packs. Marigolds, pansies, zinnias, begonias, vinca, petunias, coleus, impatiens ect. These do sometimes make seed that will grow the next year, but the blooms may not be the same color or quality as the parent and they usually take a while to establish-most people just buy new ones of these each spring. Most perennials like a little mulch over them for the winter months. Your zone is warm enough though, you may not need that. We do here in zone 5 - 6.