| 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. |
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