Perennial Focus

Ornamental grasses cover a large part of the earth. Everywhere we go, we see them swaying in the wind. They are in fields, on roadside edges, and in our gardens. Hardy to zone 4, Panicum virgatum is a native prairie grass that is particularly useful in our landscapes. It is quite versatile from a designer's point of view, being effective as a specimen, in masses, as screening, near water, and even in containers.

Switch grass takes it name from the swishing sound it makes when the wind blows. This is a sturdy grass that will remain standing throughout the winter unless buffeted by heavy snows, providing cover and food for birds during the winter.

Switch Grass will grow in full sun or light shade. Although most catalogs say that it will tolerate partial shade, it tends to become floppy in partial shade. While it does best with adequate moisture, as a prairie denizen, it can tolerate periods of drought or flooding.

One of the greatest assets of Panicum is its beautiful, relatively upright foliage that curves outward at the tips, giving it a vase-shaped appearance. Typically, the diameter is half of the height. The heights given below for various cultivars are the height in bloom. Until bloom, the foliage will be approximately one to two feet shorter.

There are two main groups of Panicum: the blue ones and the red ones. The foliage of blue Panicum is steel-blue and its inflorescences are a pale golden yellow. Several cultivars exist. 'Heavy Metal' was one of the first cultivars and is one of the shorter, columnar ones, only growing three to four feet tall. Initially, the panicles are pale pink and then mature to straw yellow.

'Prairie Sky' has narrower foliage, tolerates sandy or drier soil better, and grows stiffly, four to five feet tall with dark red inflorescences in midsummer that mature to pale yellow and then beige. Harlan Hamernik, a great horticulturist, owner of Bluebird Nursery in Nebraska and friend of mine, says that 'Prairie Sky' is the newest, bluest, hardiest, strongest and quickest" of all the switch grasses.

'Cloud Nine' grows six feet tall and wide. Its rose-colored panicles are so large that they envelop the upright foliage and tend to lean outward, hence the wonderful 'cloud' effect - so give this one plenty of space.

'Northwind' has a very tight habit with most of the inflorescences, being situated in the middle of the clump instead of arching away from it, and grows five to six feet tall. At Northcreek Nursery in Pennsylvania, 'Northwind' was the only Panicum to remain standing during a hurricane in the late 1990's.

'Dallas Blues' grows six to eight feet tall with a very strong upright habit and wider foliage, almost making it look like a blue Miscanthus (Maiden Grass). It has unusually large, finely-textured, purple-tinged flower panicles that persist throughout winter, providing visual interest as well as food for birds.

The foliage of red switch grasses varies from green to garnet-tinged green to almost completely red, and its inflorescences are a pale rosy pink. The red switch grasses also have a number of cultivars. The inflorescences of the red Panicum are pale rosy pink, maturing to pale yellow, and then to beige.

The oldest, and one of the best, is Panicum 'Rotstrahlbusch' that grows three to four feet tall. Its foliage is green in spring and summer, acquiring reddish tones in late summer as it gradually changes to burgundy-red by autumn.

'Shenandoah' was introduced about five years ago, touted for its earlier reddening, but I have been very disappointed with its growth habit. Touted as growing three feet high, it has been a very slow grower, reaching only two feet high, growing under the same conditions as 'Rotstrahlbusch'. If I could be sure that it would only grow two feet high, I could design with it as a border edging. The red foliage is quite dark and makes an excellent contrast to the greens of nearby perennial foliage.

There are several more cultivars of the red switch grasses coming. 'Praire Fire' is supposed to color up in early summer and is taller than either 'Rotstrahlbusch' or 'Shenandoah'. The foliage on this one will be very dark.

With so many choices and ways to use Panicum, you just have to find space in the landscape for it.

.Bobbie Schwartz, owner of Bobbie's Green Thumb in Shaker Hts., Ohio, is a landscape designer, consultant, free-lance writer, and lecturer whose specialties are perennial gardens and four-season landscapes. In addition to being an Ohio Landscape Association (OLA) member, she is an active member of the Ohio Nursery and Landscape Association (ONLA) and Perennial Plant Association (PPA). Bobbie is a Past President of the Association of Professional Landscape Designers (APLD), and currently serves as chair of the ONLA Plant Selection Committee. She can be reached at (216) 752-9449.