Short Ornamental Grasses for Large Groupings

Vertical Grass to 1.5 Feet Tall

• For vertical interest, plant dense groupings of Japanese sweet flag (Acora gramineus). This upright grass grows 6 to 12 inches tall with an 8-inch spread. Its lustrous foliage adds fragrance to the garden. Choose from a range of cultivars such as yellow-striped "Ogon," white and green "Variegatus" and bright yellow-green "Mimeus areus." Japanese sweet flag grows in moist soil and is hardy in U.S. Department of Agriculture plant hardiness zones 7 to 9. Another low-growing vertical grass, "Little Bunny" fountain grass (Pennisetum alopecuroides) grows 12 to 18 inches tall. Its deep-green foliage turns yellow in fall, and white blossoms add interest in late summer. Plant "Little Bunny" in USDA zones 5 to 9 in well-draining soil.

Mounding Grass to 1.5 Feet Tall

• Blue fescue (Festuca glauca) looks best when planted in dense groups. This clumping grass grows in dense mounds of blue-green foliage up to 10 inches tall. It's hardy in USDA zones 4 to 9 and grows well in sunny, well-draining sites. Colorful cultivars include "Elijah Blue," with silver-blue fronds, and "Golden Toup," a yellow-green variety. Another soft, mounding grass, prairie dropseed (Sporobolus heterolepisis) grows to 15 inches tall in a flowing, rounded clump of fine, green foliage that turns coppery orange in autumn. Prairie dropseed produces bird-attracting, fragrant inflorescences in late summer and grows well in a variety of site conditions. It's hardy in USDA zones 4 to 8.

Vertical Grass to 3 Feet Tall

• For a splash of brilliant red color that the Colorado State University Cooperative Extension describes as "exotic," plant groups of Japanese blood grass (Imperata cylindrica var. koenigii). This upright grass has a narrow spread with 2-foot-tall green foliage topped with deep-red tips. Hardy in USDA zones 6 to 9, this grass thrives in moist or wet soil, but established plants tolerate drought. "The Blues" little bluestem (Schizachyrium scoparium "The Blues") grows to 2 feet tall and has upright, blue foliage. This fine-textured grass is hardy in USDA zones 4 to 10 and adds gold color to the fall landscape. Little bluestem grows best in sunny, well-draining sites.

Mounding Grass to 3 Feet Tall

• For a mound of green foliage that turns orange and bronze in autumn, plant hakone grass (Hakonechloa macro). This grass forms 3-foot-tall mounds of soft arching fronds and grows best in cool sites with rich, moist soil. The "Albovaiegata" cultivar, a white-striped variety, tolerates warmer exposures than the species. Hakone grass is hardy in USDA zones 4 to 8. Tufted sedge (Carex elata) also grows in soft mounds. This 3-foot-tall grass has thin, arching leaves that brighten the garden with yellow and green stripes. Hardy in USDA zones 5 to 9, this grass prefers wet sites and can even survive in standing water.