How to grow HUGE Boston Ferns: 1) replant in 12-14 in diameter pots; 2) re-pot using a mix of potting soil and some horse manure; 3) water frequently (2x/day in hot weather); and 4) if they start losing their dark green color, find some good fertilizer for acid loving plants and follow the instructions.
How to grow giant ferns...
bright colored fence
I love my ZZ plant. It puts up with my shady house and less than careful maintenance. I have to keep it on a plant stand, though, because it's poisonous to kids and pets.