I don't know why it wouldn't work in Florida. There is a Raised Bed group on Facebook and people all over the world used square foot gardening along with other methods. I'm in southern California and think it works great. The mix drains well, so if you get a lot of rain, I don't think it would be a problem. Plan your planting based on the growing season in your area. There are active Master Gardener groups in Florida that can help you out.

Hi Lindsey,

square foot gardening can mostly work, but I find the need to adjust the spacing to reduce problems with fungus and blights. Florida has a much higher humidity than Utah. Plants like tomatoes need airflow to reduce pathogens. You can plant shorter things like parsley, carrots, or radishes near the tomato to leave air flow space.

Most Floridians grow tomatoes in their own pot to reduce the chance of root knot nematodes. The other night shade plants can also be affected. Make sure to rotate between plant families.

Use mulch to help keep in moisture. Also shade cloth if needed.