Have you ever looked out your window after a windy night and seen long, dry ornamental grass "blades" all over your lawn? If they haven't blown off yet, the strands of grass are probably dried and dead looking, like a shaft of hair with dried, split ends. They both look lackluster. Get a good haircut, and your whole head of hair looks fuller and shinier. Similarly, ornamental grasses will grow fuller and more vibrant if they are cut back before they begin to grow again.
Professional lawn care specialists in Maryland recommend that the best time to trim ornamental grass is just before new growth begins. You can do several things to prepare for the new growth. First, mulch around the base of the grass to protect it from freezing temperatures. Consider this a "leave-in conditioner" for the ornamental grass. Cut any falling or leaning blades frequently to prevent mold from developing under snow. The ornamental grass should be cut within four to six inches of the soil level. The sooner you cut it back, the sooner new growth will appear. If your variety of ornamental grass remains green year-round, just cut the old, dead foliage, not the whole plant. Finally, divide grass plants if they are getting too large. Lift them out of the ground and divide the root ball into two pieces. Replant them at the same depth as the original plant.
If you cut your ornamental grass early, the next windy day won't be filled with fly-aways.