A cool-season ornamental grass, feather reed grass (Calamagrostis x acutiflora) breaks dormancy early in spring and is among the first grasses to bloom. With cultivars hardy in U.S. Department of Agriculture plant hardiness zones 4 through 9, this grass provides beauty from its earliest green blades to the last of its dried, tawny plumes. Pruning in late winter allows full appreciation of feather reed's year-round ornamental interest and its burst of early spring growth.
With pruning timed to complement feather reed's annual growth cycle, all its many features can be enjoyed. The basal clump of semi-evergreen foliage comes early in spring to form a mound 2 to 3 feet tall and 1 to 1.5 feet wide. Finely textured, light-green flower plumes soon rise from the center and mature to purplish-pink in early summer on flower stalks 3 to 6 feet high. Feather reed's striking, vertical form remains attractive throughout winter. As spring approaches, it's time to make way for the new season's growth.
Before new foliage begins to emerge in early spring, cut feather reed grass back to 4 to 6 inches above the ground. Since this is one of the earliest ornamental grasses to break winter dormancy, don't delay past late winter so new growth isn't hindered. To hold the grass in place for pruning and make cleanup quick and simple, tie a length of twine around the entire circumference of the clump. Wrap tightly so it's held firm. Cut the grass to the desired height using hedge shears, and remove the bound bundle intact. Wear long sleeves and gloves to protect yourself from rough grass blades.
Versatile and tolerant, feather reed grass adapts readily to a wide variety of soils and conditions. It tolerates wet and drought, sun and partial shade. But this grass thrives in evenly moist, well-drained, rich organic soils in a location that receives full sun. A clump-forming grass with sterile seeds, still attractive to birds, it has no invasive properties and stays where it is put. Other than an annual pruning, feather reed grass requires minimal care and has no disease or pest problems. To propagate plants, divide mature clumps in early spring.
Several feather reed cultivars enjoy wide-spread popularity. Among them, Foerster's feather reed grass (Calamagrostis x acutiflora "Karl Foerster"') blooms two to three weeks earlier than the species with reddish-brown flowers. It was named the 2001 Perennial Plant of the Year. "Avalanche" (Calamagrostis x acutiflora "Avalanche") has similar flowers but variegated foliage with a white center and green margins. Both these cultivars are hardy in USDA zones 4 through 9. Hardy in USDA zones 4 through 8, "Overdam" (Calamagrostis x acutiflora "Overdam") has green foliage with white margins, the opposite of "Avalanche," and performs well in overly wet soils. In both these variegated cultivars, foliage colors will be most prominent in cool climates.
- Ohio State University Plant Facts: Calamagrostis Acutiflora - Feather Reed Grass
- Monrovia: Foerster's Feather Reed Grass -- Calamagrostis x Acutiflora "Karl Foerster"
- Monrovia: Avalanche Feather Reed Grass -- Calamagrostis x Acutiflora "Avalanche"
- Missouri Botanical Garden Plant Finder: Calamagrostis x Acutiflora "Overdam"