The Prettiest Ornamental Grasses for Your Landscape

About Ornamental Grass

Ornamental grasses stay attractive all season long and make striking accents or background plantings. They grow well into fall when many flowers are fading, and also add winter interest. See the best fall plants for your garden.

These low-maintenance plants come in a wide range of textures, forms, sizes, and colors. Scout out the boring, bare spots in your landscape that could use some four-season pizzazz.

How Do Ornamental Grasses Grow?

Ornamental grasses can be separated into two groups—runners and clumpers—based on their growth characteristics. 

1. Runners are spread by underground rhizomes or above-ground stolons. They make good ground covers, will crowd out weeds, and are perfect for holding soil in place on steep bankings. Strong runners can become an invasive nuisance though, overpowering other plantings. 
2. Clumpers are better behaved since they stay in one place. As the clump matures, it will get larger, but it won’t invade the rest of the garden, making it easier to design with. 

Ornamental Grasses for Sun or Shade

Most ornamental grasses perform best in full sun or at least 5 hours of direct sunlight daily. Foliage color will be more striking on plants that get more sun. They will grow in partial shade but will be shorter and bloom later. Their growth may be lax and floppy. 

However, sedges and rushes are especially good choices for shady locations and host many kinds of beneficial insects. They are also considered ornamental grasses because of their grasslike appearance and growth habits, even though they are not technically grasses. See more plants and flowers that grow in the shade.

Ornamental Grasses for Cool or Warm Climates

In growing ornamental grasses, heat is even more critical than light for plant metabolism. 

Cool Season Ornamental Grasses

Cool-season growers flourish in the spring and fall and are dormant in summer and winter. Some cool season clumpers are:

• Feather reed grasses (Calamagrostis) which are perfect in both full and part sun. For a great vertical accent plant, try the 6-foot-tall ‘Karl Foerster’. Its early growth makes it an effective screening plant. The plume-like flowers rise well above the foliage. Grow ‘Overdam’ for its variegated foliage. Zone 4 to 9.

• Japanese forest grass (Hakonechloa macra) is a slow grower, making neat mounds of soft arching leaves 18 inches high and 2 feet wide. Colors can range from all green to all yellow with many variegated combinations. It thrives in partial shade and is hardy in zones 5-9.

• Sedges (Carex) are cool growers that need shade. If watered regularly, the green and white ‘Ice Dance’ is one that can take full sun. For color, try blue sedge, Bowles golden sedge, or yellow-edged ‘Gold Fountains’. Sedges bloom early in the season and are the larval food for many types of caterpillars. Most are hardy in zones 5-9.

Warm-Season Ornamental Grasses

Warm-season growers like it hot and make all their growth during the summer. They are dormant in winter. Some popular warm-season native clumpers are:

• Switch grasses (Panicum) produce a fine cloud of tiny red blossoms. At 7 to 8 feet high, ‘Cloud Nine’ is the tallest, steel blue ‘Heavy Metal’ and ‘Northwind’ grow 5 to 6 feet tall, and blue-green ‘Cape Breeze’ is among the smallest at 2 feet in height. A rugged native, it is hardy in zones 3 to 10 and is a host plant for skipper butterflies.

• Indian grass (Sorghastrum nutans) ‘Sioux Blue’ has powder-blue foliage and grows up to 6 feet tall. Hardy in zones 3-9, butterflies love their pollen.

• Prairie dropseed (Sporobolus heterolepsis) forms neat clumps of fine leaves 2-3 feet tall. Its fragrant, silky blossoms rise another 2 feet above the leaves. Variety ‘Morning Mist’ has reddish flower stalks. Hardy in zones 3-9.

Beware the Non-native, Invasive Grasses

Two of the most popular species of ornamental grass are now considered invasive plants in many areas of the country. 

1. Steer clear of misbehaving Chinese miscanthus cultivars (Miscanthus sinensis). These exotics escaped cultivation, spreading via wind-blown seeds to invade and crowd out native plants. Some states have placed them on their invasive species lists. Switchgrass is a good native substitute.
2. Many pennisetums including African fountaingrass (Pennisetum setaceum) and Chinese fountaingrass (P. alopecuroides) also have joined the naughty list. Even varieties sold as sterile have been able to cross with other cultivars and produce viable seeds. Try growing native prairie dropseed instead. Despite its name the seeds rarely germinate and they are a favorite food for birds and small critters. 

Before adding any ornamental grass to your garden, check with your state extension service or go to www.invasivespeciesinfo.gov to see if it is invasive in your area.

Planting Ornamental Grasses    

Ornamental grasses are not too fussy about soil conditions. Though well-drained, fertile soil is optimum, they will thrive in poor soil, heavy clay, or dry sand and many are salt tolerant.

1. When you plant your new grass, the crown should be slightly above the surface. Planting too low can rot the crown, too high and it will dry out. 
2. Space your plants far enough apart to allow for mature growth. 
3. Use mulch to control weeds and conserve moisture but keep it 2” away from the crown. Bark mulch provides slow-release nutrients for the grass as it breaks down. 
4. Water thoroughly when planting and water deeply once a week during the first season while the plants get established. 
5. No fertilizer is necessary; it can actually weaken the plant by making the stems too tender and floppy. Compost is an acceptable supplement but don’t use manure. 
6. Once plants are established they are drought-resistant and need additional watering only in the driest times. Overwatering causes more damage than underwatering - reducing flowering and even rotting the crown.

This is a truly low-care plant, no deadheading is needed. Most ornamental grasses are relatively pest and disease free.

Let the foliage stand in the garden all winter for movement and beauty. The lacy filigree of foliage and seedheads, when covered with frost and snow, is not only lovely to look at but provides food and shelter for the birds. The foliage acts as a natural mulch, protecting the crown against cold and ice. 

When to Cut Back Ornamental Grass

In spring, cut back the clumps to 4 to 6 inches high. Wear gloves because the sharp leaf edges can cause cuts. 

As the clumps get older, they can die out in the center. Renew the plant by dividing and transplanting the new outer growth. Cut with a sharp spade or a knife; you may need to use a hatchet or an ax to divide tough clumps before digging them out. This operation is best performed in the spring. 

Learn more about dividing perennials.

Ornamental grasses are truly four season plants. Consider adding an ornamental grass or two to your garden for visual impact and winter interest.