By our calculations, you should look at sowing Early Glory about 14 days before your last frost date.
Heirloom OP Brassica which can be grown as a cabbage in colder conditions, or allowed to flower in warmer conditions to produce an early cauliflower. Improved by the Florida State Horticultural Society. 1 Well adapted to subtropics and tropics.
1 http://www.fshs.org/Proceedings/Password%20Protected/1962%20Vol.%2075/130-131%20(BURGIS).pdf