horticulture

Description
Giant miscanthus is a huge and robust ornamental grass that can stand as tall as 15' and spread out more than 8' across. The leaves are flat, but slightly folded, about an inch and a half wide, and 3' long. They are deep green with a white midvein. The leaves arch gracefully outward from stout reedlike culms (stems) up to 2" in diameter that grow upright from a central clump. The overall appearance is like a giant green water fountain. In late summer or autumn, giant miscanthus produces 18-20" silvery silky plumes that are held high above the leaves on strong stems. The plumes stay silvery-white, but the foliage turns beige and russet in early winter. The leaves eventually drop off in winter, leaving just the vertical stems. Although it is technically aclump grass and not a turf-forming grass, giant miscanthus spreads and enlarges slowly with short underground rhizomes.

Look for the name, "Giganteus" if you want this grass. It may be listed as a variety of Miscanthus sinensis, M. sacchariflorus, M. japonicus, or simply as Miscanthus 'Giganteus'.

Location
Giant miscanthus is native to Japan, the Ryukyu Islands, Taiwan, and other islands in that part of the Pacific. It has become an invasive pest in Guam and other Pacific islands outside it native range.

Culture
Giant miscanthus flowers late in the season and may not bloom at all in northern latitudes. Cut dead stems back to the ground before new growth begins.
Light: Giant miscanthus does best in full sun. It is likely to stretch for the sun and wind up falling over if planted in too much shade.
Moisture: Giant miscanthus needs lots of water during its growing season, but likes it dry in the winter. It tolerates fairly moist soils, but does best in well-drained soils with frequent watering.
Hardiness: USDA Zones 5 - 9. Giant miscanthus flowers best following long, hot summers, and it may not flower at all in zones 5-7.
Propagation: Propagate giant miscanthus by dividing the root crown. This can be done with a back hoe or steam shovel if a standard garden spade seems inadequate.