You can cut it back, but I wouldn't do it too severely and it really impacts the appearance for at least a season. For this type of Carex, I just used gloved hands to groom the plant and remove the dead fronds.

It's fairly hard to tell if what you're cutting off is actually dead, though. You don't have to cut it back, so I would just relax and let it do its thing.

Brenda

Just a little more description on the "grooming" mentioned above...run your hands from the base of the bunch out to the ends of the leaves, tugging gently. The dead should pull out fairly easily.

If you want to double check that the leaves that stayed attached are really still alive, pull one of those single leaves out from the base of the bunch, and check to see if the base of the leaf is still green & moist.

:) Since I'm in zone 5, and this plant is not really supposed to be perennial here, it took a little extra convincing for me (and everyone else who asked) that it was still alive.