I was visiting my brother in law and he has this ornamental grass
growing in his backyard. He was asking me if I know what it is and what
he should do with it for cutting, trimming etc. I told him I didn't know
but I would try to find out. It's about 4 feet tall. Any thoughts on what this is? His home is in PA zone 6.

Sorry it was getting dark when he asked and I was trying to get the pictures. If these aren't good enough for an ID I'll ask him if he can get me some better pics.