I am in Pensacola (right down the street from you) and where you have red clay we have sand!
I have resorted to a raised bed. Ours is 8x8. We started with mulch, chicken manure, top soil and our own compost. Your red clay would be a plus to this mixture. Actually, an 8x8 space takes a lot of soil...we ended up purchasing top soil from a local company..$28.00 per truck load. Much better that bags of soil from Home Depot!!
Presently, we have squash, tomatoes, bell peppers, watermelon and cantaloupe planted - a lot for a small area but it seems to be doing well.
Good luck to you!