Grassy Tactics 

ERIC'S GRASSY TACTICS:
A hungry grassy will always turn on your fly if it sees/hears/feels it. If your fly lands within the zone (circumference) of the fish, and the grassy turns, it's looking for your fly, the disturbance. Start peppering the fish with casts, until you can get your fly within 6" of its head. It takes a longer time for a bigger grassy (30" or longer) to turn, so make it easy for them. Wait for your fly to disappear, and their mouth to close, before you set the hook. Hang on, because the first run is strong. Afterwards it's a tug of war for the bigger ones. Give it a try!