Cool season Korean ornamental grass (Calamagrostis arundinacea brachystricta), also known as fall-blooming feather reed grass, thrives in U.S. Department of Agriculture plant hardiness zones 4 through 9. Late summer inflorescences blush pink-purple, fading to beige as foliage turns green-brown by late fall. The plant dims to buff by early winter, when thin vertical fruit stalks shed their grains and impart a strong architectural essence to this perennial. The best time to trim Korean ornamental grass back is late winter. It’s among the first ornamental grasses to break early spring dormancy, so don’t let it sneak up on you and produce new shoots before you get around to trimming it back.
Things You'll Need
- Clean pruning saw, hacksaw or old serrated bread knife
Comb gently through the Korean ornamental grass clump with your fingers to remove dead or dying foliage, and stray fallen tree leaves throughout the growing season. Do this as soon as you notice unsightly debris to keep the plant looking tidy, and help prevent invasion by unwanted pests and diseases. Discard the refuse immediately away from the gardening area.
Trim the plant using a clean pruning saw, hacksaw or serrated bread knife in late February or early March before new growth emerges. This allows new shoots to emerge easily without exposure to pests and diseases that dead foliage often harbors.
Grab a handful of the plant’s dead foliage about 12 inches above the ground. Trimming the plant in small sections makes it easier to manage. Pull the foliage straight up and hold the bunch taut. Prune it back to about 4 inches above the soil. Repeat to cut the entire plant back.
Clean up the trimmings right away. Don’t allow them to remain in the gardening area, where they attract bugs and infectious microorganisms.
Tips & Warnings
- Wear gardening gloves when handling Korean ornamental grass.
- Don’t burn the dead foliage on your Korean ornamental grass. Burning can do some serious damage or even kill the plant’s growing tips.
- University of Illinois Extension HortAnswers: Ornamental Grass -- Korean Reed Grass
- University of Missouri Extension: Ornamental Grasses
- University of California: Ornamental Grass
- The Ohio State University: Calamagrostis acutiflora -- Feather Reed Grass
- Bluestem Nursery: Grass Clippings -- Cutting Back Ornamental Grasses