karl forester reed grass Without being able to look at those seed heads this might also be a good contender. Could you please send close ups of the seed heads?
Pampas grass pictures It could still be Pampas Grass as well. Need a close up of the seed head as well as the leave...or where those leaves join the stem.
My experience with Pampas grass includes trying to clean out, clean up, thin or control and lots of humongous rats. Great rat housing!