Most people love to share. Just say hey really admire your flowers and was wondering if I may have 1 or 2 of them.
Most people love to and if not doesn't hurt to ask.
Or hey when you thin them out I would love a few of them.
We did it last year a house dug up tons of Variegated Ginger and after 2 weeks of alot in their drive way we stopped and ask and they gave us all of it they had dug up