Feather Reed Grass Plant Profile

Feather reed grass (Calamagrostis x acutiflora) is a cool-season, clump-forming ornamental grass that blooms early in the season and remains tall, straight, and upright throughout the growing season. Unlike many other grasses that have a weeping or floppy habit, feather reed grass looks tidy all year, even after it blooms. 

Feather reed grass is a naturally occurring hybrid cross of C. arundinacea and C. epigejos, two species native to Europe and Asia. Feather reed grass has narrow, upright blades that can be green or greenish-yellow, or variegated, depending on cultivar. The flowers (inflorescences) give way to tan seed heads that are held above the leaves and persist throughout the winter unless pruned away.

Feather reed grass is semi-evergreen, meaning it will retain its color in milder climates. It also tends to grow in well-behaved clumps, which means you do not have to worry about it aggressively spreading throughout your garden or becoming invasive. These features make them an ideal choice for most gardens.

Feather reed grass is relatively slow-growing for an ornamental grass, spreading gradually. It is normally planted in the spring from potted nursery-grown plants.

How to Grow Feather Reed Grass

Ornamental feather reed grass is a very easy plant to grow. It is normally planted from nursery-grown seedlings, not seeds. Plant it at the same depth as it was growing in the nursery container.

Since feather reed grass is an early-blooming, cool-season grass, it can be cut back in the fall. However, it looks nice all winter and many gardeners prefer to leave it standing until early spring. Just don’t wait too long in spring to cut it back, or the new grass will start to grow through the old blades, making it difficult to shear without cutting the new blades as well. Cut the plant back to about 6 inches from the ground.

Along with its easy-growing habit, feather reed grass is virtually pest-free. Fungal rust can occur after prolonged rainy periods.

Light

Plant feather reed grasses in full sun to part shade. The plants will be smaller and flop a bit if grown in too much shade.

Soil

Feather reed grass is tolerant of a wide range of soils and growing conditions, although a rich, well-draining soil with a neutral pH is ideal. It prefers slightly damp soil and can survive even poorly draining soil.

Water

This plant likes wet soils, but once established, feather reed grass is drought tolerant. Your feather reed grass will be a smaller plant if grown in a dry site.

Temperature and Humidity

Most feather reed grasses are reliably perennial in USDA Hardiness Zones 5 through 9. It is regarded as a cool-season grass and doesn't care for intense heat. In the northern part of the range, protect the crowns of the plant over winter with a layer of mulch, removing it when new growth starts in the spring. In warmer climates, the plant will perform better if it receives more water.

Fertilizer

This plant does not require any supplemental fertilizer, but organic mulch around the plant will provide necessary nutrients.

Propagating Feather Reed Grass

The cultivated varieties of feather reed grass tend to be sterile and set no seeds that could cause them to spread aggressively. They are also clump-forming rather than spreading by rhizomes. While they don't spread out of control, the clump does get larger. To prevent them from dying out in the center, they will eventually need to be divided, generally, every three to five years. They can be divided in the fall or early spring, but gardeners in cold climates will have better luck dividing in the early spring. In other zones, fall is the traditional time to divide this plant.

Varieties of Feather Reed Grass

• Calamagrostis x acutiflora 'Karl Foerster' has green leaves with reddish flowers. This 3- to 4-foot tall plant was named Perennial Plant of the Year in 2001.
• Calamagrostis x acutiflora 'Overdam' has white variegated leaves and white flowers. It grows 2 to 3 feet tall.
• Calamagrostis x acutiflora 'Avalanche' has yellow variegated leaves and golden-brown flowers. It grows 2 to 3 feet tall.

Feather Reed Grass vs. Korean Feather Reed Grass

Korean feather reed grass (Calamagrostis brachytricha) makes a nice alternative to C. x acutifloa for part-shade locations. It is a bit less upright than feather reed grass, but still a well-behaved plant that grows 3 to 4 feet tall.

Landscape Uses

Feather reed grass is very versatile, working well as a specimen plant or in mass plantings. It is a nice complement to the late-blooming colors of fall. Although ornamental grasses are not grown for their flowers, they can be quite attractive, especially when the light shines through them. Feather reed grass blooms early and retains its inflorescence all season. Most of the hybrids are sterile, so you don't have to worry about self-seeding.

This grass provides a nice architectural, vertical accent, especially in smaller gardens. Because of its upright nature, feather reed grass will create a lovely swaying screen.

Since feather reed grass is fond of damp soil, it makes an excellent choice for bog-like areas around water gardens or even around swimming pools. The compact, clump-forming growth also makes it a perfect fit in containers.