Tall Grasses for Borders

15 To 20 Feet Tall

• Among the tallest decorative grasses, the giant reed (Arundo domax) grows to 20 feet tall and has thick, upright foliage. Giant reed thrives in sunny, dry sites and produces 3-foot-tall plumes in late summer. Hardy pampas grass (Erianthus ravennae) grows from 10 to 20 feet tall and turns orange, purple and brown in fall. This warm-season grass grows in upright clumps and blooms with silver, white and tan inflorescences in late summer. Striped corn (Zea mays cvs.) grows as an annual and reaches heights to 15 feet. A sun-loving grass, striped corn comes in several cultivars, including the red- and purple-striped Red Stalker and the white, yellow, pink and green Quadricolor.

10 to 14 Feet Tall

• Ravenna grass (Saccharum ravennae) grows up to 14 feet tall and has gray-green foliage that turns orange in autumn. It produces pink plumes in summer that turn red in fall. Several grasses in the tall Miscanthus genus grow to 10 or more feet tall. Cosmopolitan (M. sinensis var. Condensatus) has green-white foliage and blooms with bronze-red inflorescences in fall. It grows to 10 feet tall and prefers sunny sites, as does the giant miscanthus (M. floridulus), a clumping grass that blooms with plumy white flowers in midsummer. Pampas grass (Cortaderia selloana) also grows to 10 feet tall. This clumping grass has arching foliage and produces feathery white plumes in late summer.

8 to 9 Feet Tall

• Several Miscanthus sinensis cultivars grow to 9 feet tall, including Goliath, a clumping grass that produces large, pink panicles in late summer, and Strictus or porcupine grass, an upright grass with yellow, horizontal stripes. Khus khus (Vetiveria zizanioides) is often grown as an annual or as a container plant. This 8-foot-tall grass has fine, upright foliage that turns copper-purple in late summer. Tall switch grass (Panicum virgatum Cloud Nine) also grows to 8 feet tall in an upright clump. This native grass has blue-green foliage and produces airy inflorescences. Tall moor grass (Molina caerulea subsp. Arundinacea) produces 3-foot-tall mounds of arching foliage topped by 8-foot-tall stalks. This cool-season grass thrives in sunny sites.

6 to 7 Feet Tall

• Indian grass (Sorphaatum nutans) grows to 7 feet tall and tolerates a range of site conditions. This warm-season grass produces long-lasting, bronze inflorescences in summer. Prairie cord grass (Spartina pectinata) and switch grass (Panicum virgatum) grow to 6 feet tall. Prairie cord grass has dark, lustrous foliage that grows in an arching mound, while switch grass grows in an airy, upright clump of narrow, blue-green foliage that turns red in autumn.