The botanical name is from the Greek kalamos, a reed, and agrostis, a grass. This highly acclaimed cultivar is one of the most versatile, attractive, and low maintenance ornamental grasses. The deep green, shiny foliage of this cool season grass appears in early spring and lasts until early winter. Loose, feathery flower inflorescences appear in June and are initially light pink in colour. As the seed heads mature, they become very narrow with a golden tan colour that lasts through the fall season. The growth habit is vertical with a tuft of foliage 2-3 feet tall and flower stems to 5 feet in height. The narrow, tight habit of this cultivar creates a 18 inch wide clump. In mild winters the foliage rosettes remain evergreen or may show some growth.

Hardiness: Grows reliably in zone 5

Light: Full sun to partial shade

Soil: Growth is optimal in well-drained fertile soils, but this perennial will tolerate heavy clay soils.

Uses: This clump-forming, highly ornamental grass is excellent used as a specimen or for a vertical effect in the landscape providing a contrast to low-mounded shrubs and perennials. Attractive hedges or screens can be created with this five foot tall grass. It is also useful for fresh or dried flower arrangements.

Unique Qualities:
This ornamental grass provides movement in the border. The softest breeze sets it into perpetual motion. Even in winter snows and frost, this grass remains ornamental. Calamagrostis x acutiflora ‘Karl Foerster’ is easy to grow and sterile flowers eliminate any chance of this grass becoming invasive.

Planting Information: Plant this cool season grass in fall or spring. It tolerates a wide range of conditions in full sun or partial shade. Growth is best in well-drained and moist fertile soils, but it will tolerate poorer drained soils. Space 18 inches apart. Water well until plants are established.

Cultivation: Calamagrostis x acutiflora ‘Karl Foerster’ is a long-blooming, low maintenance, long-lived perennial  

grass for full sun to partial shade. This grass grows best in well-drained fertile soils with sufficient moisture, but will tolerate heavier clay soils and drier sites. Fertilizer may be required to produce maximum height.

Low fertility will result in shorter plants. It is usually free of serious disease or insect problems although a foliar rust disease can occur in wet summers in situation with poor air circulation. Little maintenance is required except to cut back the stems to about 6 inches in late winter or early spring. Sterility eliminates any chance of this cultivar becoming an invasive plant or create unwanted seedlings in the garden.
Landscape Uses: Karl Foerster called Calamagrostis x acutiflora ‘Karl Foerster’ the "metamorphic grass". Others describe it as the "perpetual motion grass". The slightest breeze sets this grass in motion. The graceful movement is a highlight for any landscape. It is excellent as a specimen plant or providing a vertical accent in the landscape. Some designers use it for creating a fast developing screen. Others find that this feather reed grass is useful in patio pot containers. Floral designers appreciate this cultivar for its use in fresh or dried arrangements. Stems cut before the flowers mature will last for months in an arrangement while maintaining the golden tan colour. In heavy rain or wind the stems will dip and droop in all directions but return to vertical as soon as the storm passes.

A combination of Karl Foerster feather reed grass with various other perennials makes a dramatic effect in the landscape. Consider combinations with late summer and fall-blooming perennials such as Coreopsis, Echinacea, Liatris, and Rudbeckia. It is understandable why Calamagrostis x acutiflora ‘Karl Foerster’ is one of the best-selling ornamental grasses year after year.