The Carex buchananii in my parking strip garden is now large enough that it’s reaching out over the sidewalk and getting underfoot. Can I safely cut it back? Can it be cut to the ground in spring and allowed to start over?
Sedges like yours should not be cut back too far. The magazine Horticulture says you can “gather up the leaves in one hand and, using a pair of scissors, cut off the top third, including the long flowering stems. This will leave the plant arching out gracefully, but not trailing along the ground. It may be necessary to do this twice a year: at the beginning and end of the summer.”
Val Easton, writing in the Seattle Times (October 8, 2008) says “sedges resent being cut back too hard, so if the foliage lasts through the year untattered, just leave it alone. If the older foliage looks messy, or the tips have been burned by winter cold, trim the sedge back modestly, by no more than a third at most, in March or April.” Another thing you could do is to dig up and divide your Carex in March, and move it away from the edge of the planting bed.