QUICK FACTS ABOUT ORNAMENTAL GRASSES:

1. Hardy ornamental grasses are adaptable and can grow in poorer soils better than many other garden plants.

2. Ornamental grasses require little effort to maintain.

3. Cold hardy ornamental grasses come in many heights, colors, textures and have varying water requirements.

4. Ornamental grass seed heads and foliage add fall and winter interest.

5. Dried grasses have many decorative uses indoors and out.

6. Perennial ornamental grasses can be used as groundcovers, specimen plants, for erosion control, and as vertical design elements.

HARDY GARDENING WITH ORNAMENTAL GRASSES

Ornamental grasses haven't been so popular since the Victorian Age. Dozens of ornamental grasses are now available, and new forms are being added each year. The reasons for this astonishing rise in popularity appear to center around the practical, as well as the aesthetic merits of ornamental grasses. As the public becomes more environmentally aware, and learns more about low maintenance plants and sustainable landscapes, ornamental grasses that can tolerate extremes of drought and wetness are eagerly sought. Many ornamental grasses are also able to endure the repeated soil freezing and thawing typical of northern winters. Ornamental grasses are also a part of the growing popularity of water gardening, as marginal plantings between dry land and water.

Ornamental grasses serve many functions in the landscape. Ornamental grass foliage catches the wind, adding a sense of motion to the landscape. The native prairies of the Midwest were often described as an inland sea. Tall grasses also rustle in the wind, adding sound as a new dimension to the landscape. In a border, grasses can be used as edging or background plants, while larger specimens can be accent plants or screens. Rhizome- and stolon-forming grasses stabilize banks or serve as ground cover. Diminutive species can be utilized in rock gardens. Combining grasses with woody or herbaceous perennial plants, such as shrub roses, Sedum 'Autumn Joy', or Rudbeckia ‘Herbstonne’, help create a beautiful and low input, sustainable landscape. The dried foliage and flowers of many ornamental grasses are attractive and sway with the wind throughout the cold winter months. Many are excellent for use in floral arrangements.

Culture:

Ornamental grasses, in both foliage and inflorescence (seed head), vary greatly in size, shape, color and texture. Mature plants range in height from 6 inches (blue sedge, Carex glauca) to 14+ feet (hardy pampas, Saccharum ravennae). Grass forms vary from low mounding to fountain shaped to tall vertical. Foliage color includes shades of green, yellow, blue, red, brown and variegated, like Calamagrostis ‘Avalanche’. A number of grasses change color in the fall to displays of straw yellow, orange, red or purple, providing a wealth of choices. Foliage texture varies from fine to coarse, with blade widths from 1/8 to 1 inch. The inflorescence also varies in size and color, and may change color in the fall as well.

Although a few grasses tolerate shade, most require full sun. Some grasses or grass-like plants tolerate wet soils, but more require a well-drained soil. To become drought and pest resistant, plants require a suitable root zone. In compacted soils, even the root systems of the most drought-tolerant plants will not develop. Incorporate organic matter into the root zone to improve water-holding capacity and oxygen levels. Adequate organic matter will develop a soil with sufficient pore size to readily release water. The improved root zone will allow for maximum root expansion and water extraction from the soil. Improving the soil also will reduce irrigation frequency. Your investment in soil improvement will be returned in fewer maintenance problems and more attractive, longer-lived plants. Compost, compost, compost!

Ornamental grasses may be propagated from seed or division, and can be purchased from seed companies, mail-order firms and garden centers. Take heed when purchasing ornamental grasses that they are properly labeled with the complete botanical name, otherwise you might end up getting an invasive grass that will take over your garden rather than a well-behaved perennial ornamental grass. Box stores are notorious for mislabeling plant varieties with generic common names that tell the gardener little about the plant they are actually buying.

Generally, the improved strains, which include most of the new varieties, will not come true from seed and must be propagated from divisions. Many grasses do not transplant or propagate well after midsummer because root growth slows dramatically. Container-grown plants may be transplanted into the landscape throughout the growing season.

Since the foliage portion of the plant should be cut down to the ground and removed each fall or spring, some fertilization is required to compensate for nutrient loss. Use an organic fertilizer that is designed for lawns, such as Down To Earth Bio-Turf. A good deal of calcium and magnesium is lost when removing foliage, therefore a soil test for deficiencies of these elements should be carried out periodically and recommendations followed. Do not over-fertilize or use synthetic high-salt fertilizers on ornamental grasses, as this can lead to lodging (falling over) and disease problems.

In contrast to other flowering perennials, ornamental grasses require minimum maintenance and most species are both insect and disease resistant. However, improperly sited plants may become diseased because of poor air movement, high nitrogen soils or inadequate light. As ornamental grasses become more common, pest problems may develop. At that point, cultivar selection will be more important.

As with most plants, there are common myths or misunderstandings about the ornamental grasses. For example, many durable and hardy ornamental grasses growing in gardens are mistakenly called Pampas grass. Cortaderia selloana, the only true Pampas grass, will not grow in in Zones 5 or lower. Ordering grasses under the name of Pampas grass will result in disappointment for the hardy gardener.

Planting grasses whose dried foliage is to remain for the winter near combustibles such as a house or garage is not a wise practice. Dry grass foliage and flowers can be highly flammable. Remove foliage in the fall if a potential fire hazard is at all possible.

The first question to ask about a grass: is it rhizomatous (spreading by underground stems) or clump forming? Rhizomatous types make excellent ground covers, erosion control plants, and dense cover plantings that resist the invasion of weeds. The rhizomatous types spread at different rates laterally, some as much as twelve or more feet a year, and may be invasive. The clump formers simply increase in circumference, requiring division every three or four years. Distinguishing between the two types and locating them in proper sites will prevent a great deal of difficulties in managing the garden, and results in great satisfaction from this very desirable group of plants.

There are many grass or grasslike plants suitable as ornamentals, both native (ex. big bluestem, Andropogon gerardii) and exotic (ex. fountaingrass, Pennisetum alopecuroides 'Hameln'). Native grasses were members of the local flora before European settlers arrived. Exotic grasses are introduced plants from other states or countries. Some have escaped cultivation and become part of the local flora. Some grasses, such as little bluestem, annual pennisetums, and early flowering Miscanthus, can reseed in your garden or spread to wetland areas where they can become real pests. New grass species and cultivars should be evaluated for invasiveness before being grown for sale.

Ornamental Grass Types:

The most popular groups of ornamental grasses are Calamagrostis (Feather reed Grass) Festuca (fescue), Miscanthus, Panicum (switchgrass) and Pennisetum (fountaingrass).

Calamagrostis: Cool season grasses that bloom in northern climates in early summer. Some of the best grasses for hardy gardening, including ‘Karl Foerster’, ‘Overdam’, and ‘Avalanche’.

Fescue: This cool season, clump-forming grass requires protection from the hot afternoon sun. Blue foliage forms like ‘Elijah Blue’ are the most popular. Division in the early spring is often required to restore vigor. Regular fertilization may benefit this group.

Miscanthus: Considered the showiest group of warm season, clump-forming grasses, it has very showy flowers. A large group of grasses with considerable variability in height, blade width, etc. Select cultivars carefully to insure adequate hardiness and adaptation to your site.

Switchgrass: (Panicum)This native, warm-season, clump-forming group is becoming more popular as new cultivars become available. Cultivars with red fall color ('Shenandoah')and blue foliaged ('Heavy Metal') upright cultivars are popular.

Fountaingrass: Most members are warm season, clump forming grasses. Some may become weedy. Both annual and perennial cultivars are valuable in the landscape. Flowers are showy and are foxtail-like in their appearance.

Calamagrostis xacutiflora 'Karl Foerster' (Feather reed grass)

The Perennial Plant Association awarded the title of Perennial Plant of the Year 2001 to Calamagrostis xacutiflora 'Karl Foerster' (Feather reed grass). The botanical name is from the Greek kalamos, a reed, and agrostis, a grass. This highly acclaimed grass 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 an 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 creating 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 is understandable why Calamagrostis xacutlflora 'Karl Foerster' is one of the best-selling ornamental grasses year after year.