Common Name: Pacific Island silvergrass
Type: Ornamental grass
Family: Poaceae
Native Range: Japan, Ryukyu Islands, Taiwan, Guam
Zone: 6 to 9
Height: 8.00 to 12.00 feet
Spread: 2.00 to 4.00 feet
Bloom Time: August to February
Bloom Description: Reddish tan
Sun: Full sun
Water: Medium to wet
Maintenance: Low
Suggested Use: Rain Garden
Flower: Showy, Good Cut, Good Dried
Leaf: Colorful, Good Fall
Attracts: Birds
Other: Winter Interest
Tolerate: Drought, Dry Soil, Black Walnut, Urban Conditions
Culture
Easily grown in average, medium moisture, well-drained soil in full sun to part shade. Tolerant of a wide range of soils from well-drained sandy soils to the heavy clays present in much of the St. Louis area. Prefers moist soils. Best in full sun. Less vigorous with decreased flowering and tendency to flop in too much shade. Tolerant of summer heat and humidity. Clumps slowly expand in circumference by short rhizomes, but typically retain tight clump shape. Foliage should be left standing throughout the winter for visual interest and crown protection. Cut foliage close to the ground in late winter just before new shoots appear. Propagate by division of the crown. This grass will reseed to the point of being invasive.
Noteworthy Characteristics
Miscanthus floridulus, commonly called giant miscanthus, Pacific island silvergrass, or giant Chinese silver grass, is noted for its large size, its somewhat coarse foliage and its feathery inflorescences which have a prominent central rachis as opposed to the tassel-like inflorescences of the popular Miscanthus sinensis and its cultivars. It is native to lowland areas in Southeast Asia and the Pacific Islands and will generally grow in wetter soils than most other species of Miscanthus. It is also one of the tallest of the eulalia grasses. It has escaped cultivation and is considered a noxious weed in Hawaii. Features a massive upright foliage clump rising 6-8' tall of wide (to 1.5"), arching, green leaves on erect, tough, vertical stems. Tiny pink-tinged flowers in feathery inflorescences appear in late summer on stalks rising well above the foliage to 8-12' tall. Inflorescences turn silvery as the seed sets, with the continuing flower effect of the plumes lasting well into if not through the winter. Foliage acquires purplish tints in autumn, gradually turning to uniform tan by winter. Leaves often drop to the ground during the winter leaving only the stiff stems (culms).
Genus name comes from the Greek words miskos meaning a stem and anthos meaning flower in reference to the stalked spikelets.
Problems
Miscanthus mealybug and miscanthus blight are becoming significant problems in some areas. Miscanthus mealybug causes stunted growth and is difficult to eradicate because it lives inside the stems. Miscanthus blight is a fungal disease which attacks the blades and sheaths. Leaf rust may occur.
Uses
This ornamental grass needs a large space. Accent, specimen, grouping, mass or screen. Borders, meadows, wild gardens, cottage gardens, naturalized areas, low spots or pond/water garden peripheries.