Also, many Mediterranean plants work fairly well in Florida. Sandy soil is also a big problem for me. Have added lots of leaves that the neighbors seem to think of as a problem instead of a solution. White clover just got seeded in and is sprouting, pigeon peas do fine in the sandy soil and are starting to provide a good mulch. Swales to retain
water and deep-rooted perennials to use the water are a good combination. Sickle-pod and spanish needle are two very common 'weeds' here ... many people hate them for various reasons, but they are pioneer species that rebuild the soil in the early stages of succession.
Lemongrass quickly makes a decent "no-dig
swale" - planted right, it can form a solid barrier that traps water and sediment. In the north of Florida, the West Indian strains are better than the East Indian strains (much more cold resistant), but they are not as good as the East Indian strains for culinary uses.
Citrus and avocado have been two good choices, but both face some serious medium-term issues due to introduced diseases.
Here in the north, olives, pomegranates, figs, mulberries, loquat, pears, plums all work, along with persimmon, paw-paw, cherry of the rio grande, jaboticaba, sapote, muscadine grape, feijoa.
I was just reading about a grower's coop for hybrid chestnut being formed in central Fl to do processing and marketing, and then there are pecans. Hybrid hazelnuts might work if the right genetics were used ... most strains were developed up north and have not been tested here.
Various bamboos do well (too well, according to some) and can provide edible shoots and
wood.
Bananas, chayamansa, chayote/mirliton, and cassava are fair to marginal or poor in the north of the state, but do better where the frost is not so severe. Have had moringa for two seasons, it also seems to under-perform compared to its reputation, may be a soil issue. Jerusalem artichokes and mints have reputation for taking over once established, but my
experience is that they fade out in a season or two.
One traffic intersection I pass by regularly has an island filled with prickly pear, and that small space is now packed with a few hundred pounds of cactus pear fruit - too much traffic there for me to think favorably about eating them, but clear proof that Opuntia does well here.
For caffeine lovers and a cash crop, there is tea (Camellia sinensis) and the
native Yaupon.