Hi - looking for a bit of guidance. We planted maiden grass in planters on our roof deck in New York 2 years ago. We planted 36 in total and they came back great last year. This year, none have come back so far. Attached some photos including photos of one we dug up and split to see how the clump and roots look. Is it possible they all succumbed to the brutal winter? Or perhaps they are too cramped in the planters? Greatly appreciate any advice.