Some Florida Native plants that should be beneficial to the environment:
Beach Sunflower, Helianthus debilis
Blanket Flower, Gaillardia pulchella
Calamint, Calamintha georgiana
Frostweed, Verbesina virginica
Giant Ironweed, Vernonia angustifolia
Goldenrod, Salidago fistulosa and Solidago sempervirens
Tropical Milkweed, Asclepias curassavica
Rosinweed, Silphium asteriscus
Sea Ox-Eye Daisy, Borrichia frutescens
Spiderwort, Tradescantia ohiensis
Tickseed, Coreopsis leavenworthii
Also I like the idea of a community garden.