PENNISETUM. Fountain grass. Widespread, mostly in the tropics. These are mostly clumping perennial grasses with arching, narrow leaves and distinctive brushlike clusters of flowers. Both foliage and flowers can be quite colorful in some species. They are useful in drifts and borders. Some, unfortunately—the typical green leaved form of P. setaceum being a prime example—have serious invasive potential. Sun or light shade, most soils, moderate watering. Hardiness varies.
alopecuroides. Chinese pennisetum. This species makes dense clumps, up to 3’ tall, with bright green leaves and variously colored flower spikes on arching stems. ‘Moudry’ is a particularly showy selection, growing about 2' tall. It has dark, shiny leaves which color well in the fall. The flower “brushes” are greyish brown when they first appear, becoming almost black in fall. ‘Hameln’ is a more graceful plant with narrower leaves and cream-colored flowers, aging pale tan. ‘Little Bunny’ is a miniature selection, with radiating stems only 5-6” long and unusually shiny, dark green leaves. Most can be invasive in well-watered gardens. Hardy to 15oF or less.
orientale. I have never been overly fond of this species, for reasons I can’t fully express. Yet gardeners insist on planting it in great numbers. True, it makes generous fountains of arching 1-3’ (more often 2’) stems, with narrow 4-8" leaves, though those of the prevalent forms tend to be a little pale and unexciting. The narrow interrupted flower clusters have a fluffy look; their initial color is cream-white, usually with a pink blush. Fortunately they do not seem to result in many unwanted volunteers. ‘Tall Tales’ is a robust cultivar, recently introduced. It grows at least 3’ high and has longer, broader, brighter green leaves and taller flower stalks than previous material. 10oF. or less.
setaceum ‘Cupreum’. Fountain grass. A particularly showy form of this long-cultivated species, unfortunately rather tender outdoors. The stems are erect, with narrow 1-2' leaves. Both stems and leaves are purplish-bronze in color. Gracefully arching, red-tinged flower clusters are held above the foliage in summer and fall. ‘Eaton Canyon’ is a similar selection. It is distinguished by somewhat more slender, graceful stems, narrower leaves and a mixture of bronze and green shades. Both are striking specimens for large tubs. The first selection, at least, sets little viable seed and should have low invasive potential; the jury is still out on the second. Winter deciduous, but not reliably hardy below 25oF.