Feather reed grass is the common name for several types of Calamagrostis, an upright ornamental grass species with wheat-like flowers. A cool-season grass, Calamagrostis breaks dormancy in April with a flush of vivid green. Foliage reaches 3 feet tall and flowers appear in June, rising over the foliage to 6 feet. The flowers gradually turn tan and remain into winter. Feather reed grass grows in clay and light shade, but it prefers enriched soil and sun. "Karl Foerster" feather reed grass (Calamagrostis acutiflora x 'Karl Foerster') is the variety grown most often. Feather reed grasses are clump-formers and are hardy in USDA Plant Hardiness Zone 5 to 9. To care for feather reed grass, cut the plant back in spring and provide regular, thorough watering.
Choose a site in the full sun. Feather reed grasses like well-drained soil. If necessary, amend with sand to improve drainage. Add organic material, such as compost, to hold in moisture. Work the amendments into the soil.
Dig a hole 8 to 10 inches deeper than the rootball of the grass and about 5 inches wider on either side of the plant. Add some planting mix to the hole and mix with the existing soil. Water the mixture and wait several minutes for the water to drain.
Take the grass from its container and loosen the roots if they're tight in the pot. Set the plant in hole and back-fill with the existing soil. Adjust the grass to the center of the hole as you back-fill. Gently press down the soil around the grass until you reach the top of the hole.
Adjust the grass so that the soil level is the same as when the plant was in the pot. Water the plant thoroughly.
Water every few days the first week after planting. Water deeply every 2 weeks.
Mulch after the ground freezes with straw or leaves.
Cut back feather reed grass to about 6 inches high in the early spring. Fertilizing lightly with cow manure or an organic fertilizer for lawns is optional but not necessary.
Water thoroughly once every two weeks, especially during the heat of the summer.
Leave foliage on the feather reed grass until spring. Foliage provides protection against the cold.
Divide the plant in spring. Place a shovel several inches away from the base of the grass.
Dig down and gently lift entire clump.
Place clump on its side in the shade and gently pull apart large sections of the roots until you have several clumps. Use pruners or a spade to separate the roots.
Water the clumps and keep them in the shade until you replant them.
Space clumps 2 to 3 feet apart. Follow planting instructions in Section 1.