Happy to see the perennial brassicas / tree collards at my family's thriving so well! They're almost half as tall as I am!
These are a mix of the EFN's perennial kale grex and open-pollinated seeds from the "Michigan" strain from Project Tree Collard. They should be able to survive 0-10°F (-18°C to -12°C) and will hold well into winter. Growth usually resumes in February.
If you want winter greens, these are where it's at!