Plant Of The Month: Sept. 2000, Pennisetum

How to Grow
Give pennisetums full sun and average to rich, well-drained soil. Sow seeds indoors 6 to 8 weeks before the last spring frost date at 65 to 70 degrees F. Or sow outdoors on the last frost date. Water regularly, especially during dry weather. Where hardy, they can be grown outdoors year-round. In the north, grow them as bedding plants replaced annually or as tender perennials - dig the plants indoors to bring them in for overwintering in a sunny, cool (55 to 60 degrees F) spot. In areas where they are marginally hardy, mulch them heavily with salt hay, weed-free straw, or another dry mulch over winter. Plants self-sow and may become invasive.

P. setaceum p.
p. seh-TAY-cee-um. Fountain Grass. (pictured above right)
A tender, 3-foot-tall perennial, hardy from Zone 9 south, with plumelike, 1-foot-long, pinkish or purplish flowerheads in late summer and fall. 'Purpureum,' also listed as 'Atropurpureum,' bears purple leaves and red-pink flowers. 'Burgundy Giant' reaches 5 feet and has purple-maroon leaves. Tender perennial or warm-weather annual.

P. villosum
p. vil-LOW-sum. Feathertop. (pictured at right)
A tender, 2-foot-tall perennial, hardy from Zone 9 south, with plumy, cylindrical, 4- to 5-inch-long, green or white flowers that mature to purplish seed heads. Tender perennial or warm-weather annual.

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More Annual Ornamental Grasses
While the best-known ornamental grasses are perennials, there are a few handsome annuals that are worth including in beds and borders. The following species are covered in individual entries in Taylor's Guide to Annuals.

Briza. This genus contains two species of attractive annuals grown for their loose racemes or panicles of spikelets ("flowers") that hang from very fine stalks and as a result quake and flutter in the slightest breeze:

B. maxima, big quaking grass, reaches 1-½ to 2 feet and bears branched panicles of nodding, 1-inch-long spikelets that appear from late spring to late summer and ripen from green to red-brown-, gray-, or purple-flushed to straw-colored.

B. minor, little quaking grass, is 6 inches to 1-½ feet tall with nodding, ¼-inch-long spikelets in loose panicles. It blooms from early summer to fall and flowers are green, often purple-tinged, and ripen to pale tan.

Grow both these species in full sun to light shade and average to rich soil that is well-drained and remains evenly moist. Sow seeds outdoors in fall or in spring after the last spring frost date. Or sow indoors in individual pots six to eight weeks before the last frost and transplant with care. The flower heads are attractive in mixed plantings, or dry them to use in arrangements.

Hordeum. This genus contains the agricultural crop barley as well as one species commonly grown as an annual ornamental grass and used in dried flower arrangements:

H. jubatum, squirrel-tail grass or fox-tail barley. This is a 2-foot-tall annual or perennial hardy from Zone 4 south that bears feathery, 5-inch-long flower spikes that are green flushed with pale pink or purple and ripen to beige. Give it full sun and average, well-drained soil. Sow seeds outdoors a few weeks before the last spring frost date or in late fall for germination the following spring. (Plants resent transplanting and are best started outdoors where they are to grow.) Plants self sow, and can become weedy.

Zea. Although commonly known only as an agricultural or vegetable-garden crop, some forms of corn - Zea mays - deserve a place in ornamental plantings, especially variegated-leaved cultivars. Like agricultural forms of corn, variegated cultivars are annuals with lance-shaped, 3-foot long leaves.

'Variegata' is a 3- to 5-foot-tall cultivar with leaves striped in cream and white. 'Harlequin' is about the same size and has leaves striped with green, red and cream. Both come true from seeds. Plant them in full sun with rich, well-drained, evenly moist soil. Sow seeds outdoors after the last frost date once the soil has warmed up to at least 55 degrees F. Germination takes about two weeks. Or sow indoors in individual pots four to six weeks before the last frost date at 70 degrees F. If you want ears to form, plant in drifts or blocks to encourage wind pollination, or hand pollinate by dusting pollen from the male flowers onto the silks. Water during dry weather, and mulch plants to keep the soil evenly moist.

For the Plant Of The Month index click here.

Ellis is also the author of "Taylor's Guide to Growing North America's Favorite Plants: A detailed, how-to-grow guide to selecting, planting, and caring for the best classic plants." (Houghton Mifflin, 1998, softcover). Country Living magazine called this comprehensive reference "The 'must-have' gardening book of the year."