Ornamental Grasses

The current popularity of ornamental grasses has not been so grand since the Age of Queen Victoria. Scores of ornamental grasses are now in use with many new forms continuously being added. Speculation as to the reasons for this astonishing rise in popularity appears to center around the practical, as well as aesthetic merit of ornamental grasses as a whole.

As the public becomes increasingly aware of environmental forces in the Midwest landscape, many of the ornamental grasses that have an inherent ability to handle both the drought years as well as the wet years, are eagerly being sought. Another valuable environmental characteristic of some of the ornamental grasses is the ability to endure the continuous freezing and thawing of soils typical of the Midwest during the winter. There are also non-prairie type grasses that will thrive in relationship to water such as around ponds. Care should be taken in selecting ornamental grasses to match specimens to the extremes of a given site.

During the growing season, the ornamental grasses range in height from 6 inches to 14 or more feet and can be used as accent plants, ground covers, screens, border edgings, or as companions with a wide range of flowering herbaceous plants. Color of foliage in the growing season includes shades of green, green/yellow, green/blue, blue, red, brown, and variegated. Flowers vary in form, inflorescence, size, color and time of bloom providing a wealth of choices. Dried foliage and flowers on many ornamental grasses are attractive and will gracefully sway with the wind in the cold months adding a new dimension to the winter garden. Many are excellent for use in floral arrangements.

Culture

Ornamental grasses are propagated from seed or division, and can be purchased from seed companies and garden stores. Generally, the improved strains, which include most of the new varieties, will not come true from seed and must be propagated from divisions. Grasses do not transplant or propagate well after mid-summer 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, fertilization is required to compensate for nutrient loss. A 10-10-10 fertilizer may be applied at a rate of 1 to 2 pounds per 100 square feet. 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.

Cautions

As with most plants, there are common myths or misunderstandings about the ornamental grasses. For example, many durable and hardy ornamental grasses growing in Ohio are mistakenly called Pampas grass. Cortaderia selloava, the only true Pampas grass, will not grow in the state of Ohio. Ordering grasses under the name of Pampas grass will result in disappointment in this region.

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

The first question to ask about a grass when purchasing or receiving a gift is if it is rhizomatous (spreading by underground stems) or a clump former. 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. The clump formers simply increase in circumference requiring division every two or three 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.