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Perennial Plant of Year 2001: Calamagrostis xacutiflora 'Karl Foerster' |
2001 Perennial Plant of the Year
The Perennial Plant Association has awarded the title of Perennial Plant of the Year 2001 to Calamagrostis xacutiflora 'Karl Foerster'. 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 color. As the seed heads mature, they become very narrow with a golden tan color 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.
History
Calamagrostis xacutiflora 'Karl Foerster' is reported to be a natural hybrid
of Calamagrostis epigejos and Calamagrostis arundinacea. It was introduced
to the nursery trade and general public in 1950 by Karl Foerster in his book Einzag der
Graeser and Fame die Gaerten (The Use of Grasses and Ferns in the Garden), under the
name of Calamagrostis epigejos 'Hortorum'. According to Mr. Foerster, the source
for the plant was the Hamburg Botanical Garden. The Foerster Nursery also listed this
grass in their 1939 catalog but as an annual, not a perennial, grass. It was imported into
the United States from Denmark in 1964. Since that time, this highly acclaimed ornamental
grass has been distributed and has grown well in hardiness zones from 4 to 9.
Propagation
This excellent member of the Poaceae family is propagated by division. This simple
propagation method may be done in the fall or spring. If propagated in the greenhouse in
liner flats a small division should be used. For outdoor production, a division of 5-7
viable eyes should be used. For landscape plantings large clump division may be done in
the fall with a good show of flowers the following spring. Smaller clumps will require a
second growing season to fully develop a mature flowering effect.
Cultivation
Calamagrostis xacutlflora '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 situations with poor air circulation. Little maintenance is required except to cut back the stems to about 6 inches in late winter or early spring. In areas with mild winters the foliage may remain evergreen. This ornamental grass is a cool-season grass, which allows planting or transplanting in spring or fall. Sterility eliminates any chance of this cultivar becoming an invasive plant or create unwanted seedlings in the garden.
Landscape Uses
Calamagrostis xacutlflora 'Karl Foerster' is called 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 and will survive most winters without winter
protection. 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 color. 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
blooming perennials such as Coreopsis, Echinacea, Liatris, and Rudbeckia It
isunderstandable why Calamagrostis xacutlflora 'Karl Foerster' is one of the
best-selling ornamental grasses year after year.
Information and photography courtesy of Perennial Plant Association.
