Helictotrichon sempervirens, blue oat grass: prune it in spring?
I am pondering to use this grass on a green roof in small groups. I havent dealt with it before. I know that it loves poor soil and full sun and can be (semi)-evergreen.
So, do you cut back those tussocks in spring or rather let it grow? Does it get bald patches after a while and needs dividing?
Does it self seed much?
Thanks for your hints or comments, bye, Lin