When I stocked my HBG there were only fhm and gsh in the pond that were originally stocked the year before so tons of forage plus I feed every evening. Its been about a year since the HBG were stocked and they are pushing 6 inches some bigger than others but I Can't believe how fast they grow and how big they are in one year. After how many years do they quit growing? 2 lbs is goal for these!
My experience is that their growth will explode out of the gate, climb steadily and rapidly for 1.5 - 2 years, then slow dramatically. Ours tend to be a very heavy bodied fish, more so than our northern gills, and they will use that to their advantage on light tackle......they will pull like a freight train.