You’ve enjoyed several months of winter interest from your ornamental grasses, but it’s time to haul out the hedge clippers and/or chainsaw if you live in Colorado and it’s February. It’s time to cut back. It may be hard, but if your dead blades and seedheads
are still standing when the green blades grow in, your grasses will look just plain weird. And they won’t be as healthy as they could be.
So, how far should you cut them back? To about six inches above ground. You may not be able to cut that low with some of your larger grasses, but get them down to a foot or so if you can. Cutting back is easier if you tie the grass blades together with a piece of twine.
Once the new growth comes in, it’ll hide the grass stumps.