I have a number of Cyperus alternifolius in 5-inch pots, from last year. The
dead foliage has been left on during the winter because it looks quite
interesting but I don't know what to do with them now.

The stems are either completely brown (and obviously dead), or dead at the
top and green near the soil. My gardener's instinct tells me to cut them off
just above the soil but as the pots are full of stems I can't see where new
shoots will have room to grow. Perhaps I should break them up and re-pot?

Advice would be greatly appreciated.

Eric