Hopefully you have given the some room to grow, but they are a pretty slow growing tree. I have seen in pots and in the ground all over FL. Either way works, but I haven't seen many trees over 15 ft tall. The reds seem to stay shorter and squatty. Now Truncaflora I have seen very large, they seem like faster growing. But over the next 5 years I dont think you will have much to worry about growth, you can always shape and trim the trees too.