Green Duke (hybrid)-- Medium sized plants produce most of their heads within a 2 week period. Average head size is 5 1/2" in diameter and nearly 1 lb. in weight.  There is a lot of variability in head size though, ranging from 4"-8" in diameter.  It produces good quality, medium sized side shoots for 3 months.  Each plant averages a total weight of nearly 2 1/2 lbs., with 1 1/2 lbs. side shoots.