Florida incorporates the USDA Hardiness zones of 8 to 10 so the coldest plants that will thrive here is zone 8. The best flowers to grow in Florida will not have zone ratings below this number. Florida has plants and flowers that are tropical. Any of the following choices will be hits in a Florida landscape.
Princess Flower, or Tibouchina urvilleana, is from the Melastomataceae, or meadow beauty, family. It is an easy and fast growing evergreen that gets 15 feet long that makes a 10 to 12 foot mount. Leaves are green and velvety and 2 to 4 inches long. Summer purple flowers are 3 inches wide. Plant a princess flower plant in rich fertile soil and moist but not soggy soil. Propagate via clump division or by softwood cuttings
Lemongrass, or Cymbopogon citratus, is from the Poaceae/Gramineae, or grass, family. It is a fragrant fast growing evergreen perennial. Clumps of lemongrass get 6 feet tall and 4 feet wide. Evergreen straplike leaves are half to one inch wide. Leaves are used medicinally and in flavoring foods. Plant the lemongrass plant in any soil in bright sun or light shade. Propagate via spring or summer clump division and by seed.
Daffodil, or Narcissus spp., is from the Amaryllidaceae, or amaryllis, family. It is a fragrant drought tolerant perennial that attracts butterflies. Daffodil leaves get 6 to 30 inches long with flower stalks of 4 to 24 inches tall. Flowers are white, yellow, red, pink, or orange. Plant a daffodil in rich well drained soil in morning sun and partial shade. Propagate via seed or bulb division.
Cassava, or Manihot esculenta, is from the Euphorbiaceae, or spurge, family. It is a drought tolerant perennial. Dark green leaves get 12 inches wide with leaf stems of 24 inches. Plants can get up to 20 feet tall with 8 to 30 inch roots. Plant cassava plants in poor soil in full early sun with partial afternoon shade. Propagate via stem segments.