By Mary Gold, Sonoma County Master Gardener
Pennisetum orientale is one of the most graceful of all ornamental grasses and is perfectly suited for our Sonoma County dry summer climate. The genus Pennisetum is made up of approximately 120 species, but it is specifically P. orientale that is on our list of Sonoma Superstars. Pennisetums are rhizomatous, or stoloniferous, and are clump-forming grasses found in woodland and grasslands in tropical, sub-tropical and warm-temperate zones worldwide. The species P. orientale originates in China, Southwestern Asia and Northern India. It is a mound forming, densely tufted, deciduous perennial grass with upright or arching, narrowly linear green or gray-green leaves. P. orientale’s impact comes from the soft, long-bristled, pinkish spikelets that are formed in long, narrow panicles and resemble bottle brushes or bunny tails that sway in the breeze and, when lit from behind in early morning or late afternoon sun, absolutely glow.
P. orientale should be planted in full sun in well-drained soil. It will tolerate some shade in the hottest of micro-climates. It may be propagated by seed or by dividing the root mass, which widens each year and usually eventually requires some division. It is drought tolerant when established and deer resistant. All of these properties serve it well in my front yard, which is often visited by deer that wander over from the open space hills across the street. Since my yard is relatively small, I have only one, planted with Echinecea, Rudbeckia, Tagetes lemmonii (Mexican bush marigold) and Santolina
P. orientale beginss blooming in June and the blossoms persist until frost. As the year proceeds, those pink panicles mature to a light brown. The foliage turns straw-colored in winter, which gives this hardy grass almost year-round interest. In January or February the plant should be cut very low, about three to four inches from the crown of the plant. If the plant needs to be divided, do so in early spring just as the new growth begins to reappear. When planting P. orientale, make sure the crown is not planted below the soil’s surface for this will cause it to rot in the center. After some time, the center of the plant may begin to die out, but this is fixed easily by clearing out that area and dressing it with compost. The plant will quickly begin to fill in again.