Pennisetum setaceum 'Rubrum'
Photos courtesy of Sally Benson
"Graceful" is a word that's often used to describe ornamental grasses, but it's used because it's apt. So many selections can be described as "arching gracefully" or having "graceful plumes," and this is the case with Pennisetum setaceum 'Rubrum', purple fountain grass. It has long, slender foliage that tends to sway and arch in a graceful manner, and the foxtail inflorescences seem to float and weave - yes, gracefully - in the breeze.
Name: Pennisetum setaceum
Purple fountain grass
Zones 8 to 11
2 to 4 feet in containers; up to 5 to 6 feet
2 to 3+ feet
Stunning container plant in areas where it's not considered perennial; borders, focal point
Rich, deep burgundy foliage is long and narrow, arching gracefully to an average of 3 feet in containers or up to 5 feet when planted in the ground; slender stalks hold foxtail inflorescences that emerge dark red-purple and fade to light tan, often retaining a purple blush as they fade, giving the fluffy plumes a gradient hue
Although it's winter hardy only in zones 8 to 11, purple fountain grass grows quickly and offers an impressive presence for up to six or seven months in the ground and in containers in my Zone 5 location. Sadly, despite encouragement from several sources, many attempts to overwinter this grass in a garage, a basement and even a greenhouse have proved futile. So, even though new plants must be purchased each year, it's a happy task. And it can be a task finding plants, as they tend to be snapped up as soon as they hit the displays. Although it's a tender perennial, it's a good idea to consider this a three-season annual north of the Mason-Dixon line.
In spring, the long, narrow, deep red to purple foliage begins to elongate and the plant forms the typical fountain shape, providing a certain elegance to just about any garden setting. The rich color contrasts nicely with bright green emerging foliage and often serves to highlight the attributes of other plants as they fill in. But come mid to late summer, when purple fountain grass begins to send up its exceptional flowers, nothing can compare.
Showy and slender, burgundy foxtails begin to emerge atop narrow stems that reach a foot or so above the foliage, and when the inflorescences "bloom," the soft and fuzzy spikes resemble elongated bottle brushes. But they are flexible and arching, giving the plant an almost celebratory look as the stalks wave in the slightest breeze. Flowers begin to fade almost immediately, but the purple remains at the core while outer tips turn soft pink and then tan. With a couple of dozen flowers emerging on each plant - many at various intervals - there's bound to be a foxtail at nearly every phase and color of development, so the display can last upwards of a few months.
The latest I have removed the plants from my entryway was the weekend after Thanksgiving, long after several frosty nights: They were still attractive, but I was eager to put the pots away for the winter. So I cut the remaining plumes and brought them inside to enjoy, extending the season until Christmas, when a display of pines seemed more appropriate.
No insect or disease problems have been noted. The species has been reported to have invasive tendencies in the Southwest, including Arizona, California and Nevada, but because 'Rubrum' rarely sets seed, it is not considered to be a problem.
Given full sun, average garden soil or potting mix and regular watering, P. setaceum 'Rubrum' will perform in nearly any style of garden. From great swaths in highway medians or on corporate campuses, to individual plants in a patio container, there's an appropriate site for this plant nearly everywhere. It's a workhorse, but it's a graceful one.
Editorial Director, American Nurseryman