You need to start planting plants that you can use as a chop and drop mulch like Tithonia diversifolia or even Bidens alba. Florida soils don't act much like northern soils the main thing you should go for is shading the soil to increase moisture holding ability, plant native grasses with deep roots that will draw the soil moisture upwards. Start with really drought resistant legume type plants like acacia, palo verde, and grow things underneath them as nurse trees. Shade is your friend here I grow tomatoes in near total shade! Check out echo farms for seed ideas, and also consider native plants like muscadines , everglades tomatoes tried and true things like that.
