Ornamental grasses are great additions to the landscape. They offer color, texture, movement, and a bit of sophistication to the garden. Ornamental grasses are grown for their ornamental colors, patterns, forms, and/or flowers.
While many of them are taller, clump-forming, and bloom late in the season, there are ornamental grasses of all heights, growth patterns, and bloom times that can brighten the landscape in any season, including winter.
Care
Ornamental grasses are low-maintenance perennials. Most thrive in sunny sites, although a few species will tolerate part shade. They grow in a wide range of soil conditions with species that thrive in dry, well-drained, or wet soils. While small in the nursery, many can get quite large in just a couple of years, so check the labels carefully for mature size and site preferences.
Once established, grasses require minimal care, needing watering only during periods of drought. Ornamental grasses rarely need fertilizer. If growth is pale, weak, or floppy, scatter some granular fertilizer around them in the spring.
Let grasses and their ornamental flower heads stand all winter. Even when tan and dead, they are quite attractive after a snowfall. Cut back ornamental grasses in early spring (April) before new growth appears. Cut back the grasses to within 2 to 4 inches of the ground with hand shears, lopping shears, or hedge trimmers.
Planting
Ornamental grasses are often sold as containerized plants. They can be as small as plugs or in large, 5 to 10-gallon containers.
In Iowa, spring and early fall are good times to plant ornamental grasses. This typically occurs from mid-April through May and late August through September. When planting in the fall, allow at least 4 to 6 weeks before the ground freezes for the plants to become established.
Planting starts with digging a hole at least twice as wide as the container. The depth of the hole should equal the depth of the soil in the container. Pull the plant out of the container by squeezing the sides of the pot and then gently pulling the root ball out. Carefully loosen the root ball and roots, especially those roots that are circling the root ball. Ornamental grasses frequently have abundant roots in the container. Set the plant in the ground at the same level as it was in the container, and backfill with the soil that came out of the hole.
After planting, keep the newly planted ornamental grasses well-watered through the entire first growing season. Regular watering is one of the most beneficial things to help new plants establish quickly and successfully. If conditions are abnormally dry in the second and third growing seasons, be sure to provide water.
Propagation
While some ornamental grasses can be successfully propagated by seed, most are best propagated through division. Propagation is needed when plants become too large and to help control the spread of some species. Some species can remain in place for many years without needing division. Several clump-forming ornamental grasses develop dead centers in their crowns as they age. Over time, the dead area becomes obvious and unattractive. Divide these species when you notice the dead spot, and discard the dead portions when breaking or cutting the root system apart.
Learn more in this article: How to Divide and Transplant Perennials.
Using Ornamental Grasses in the Landscape
Ornamental grasses can be planted to serve many functions. They work well as specimen or accent plants. Tall grass species and varieties can be used as background plants for smaller perennials and annuals, as well as for creating screens. Smaller grasses can be placed within rock gardens or used to edge beds. They are great additions to perennial borders and beds, as well as landscaped beds with a mix of woody shrubs, trees, and perennials. Ornamental grasses pair well with spring-blooming bulbs like daffodils, tulips, and crocus. Since the leaves of ornamental grasses usually emerge later in the spring, they are ideal for allowing the early-emerging spring bulbs to take center stage and then mask the dying foliage later in the spring when the grass leaves fully emerge.
Ornamental grasses provide year-round interest, which is something many other herbaceous ornamental plants cannot do. In spring, you can enjoy the fresh green leaves. Plume-like flowers provide beautiful accents in summer and fall. Some species have notable fall color of reds and yellows. And most stand tall all winter with their dried leaves and flowers, providing something interesting to look at even in the depths of winter.
Another excellent benefit to installing ornamental grasses is their ability to provide a sense of motion and sound to the landscape. Due to the grasses' thinness and flexibility, the slightest wind causes them to move continuously, adding motion to an otherwise static garden. The movement of ornamental grasses also creates a pleasant rustling sound, adding yet another dimension and benefit to the landscape.
Ornamental Grasses for Iowa
Several different species of ornamental grasses are well-suited for Iowa gardens and landscapes. The following article gives more information about some of the more popular and easy-to-grow ornamental grass species and cultivars for the landscape.
With numerous ornamental grasses available to home gardeners, it can be challenging to select the right one for your landscape. The following article includes lists of ornamental grasses (and closely related sedges and other grass-like plants) for various growing conditions, as well as those that possess similar characteristics. Use these lists to find the ornamental grass best suited for your landscape.
Selecting Ornamental Grasses for Your Landscape
More Information
- Grasses: 30 Special Features and Uses from the University of Minnesota (PDF)
- Ornamental Grasses with Winter Interest (PDF)
- Fall-Blooming Perennials
- Perennials with Winter Interest
- Late-Season Perennial Flowers (PDF)
- Perennials with Fall Color
- Perennials for Sun (PDF)
Photo credits: 1: Aaron Steil; 2: Aaron Steil; 3: Aaron Steil; 4: Aaron Steil; 5: Aaron Steil