LSU AgCenter Horticulturist
(11/06/20) Ornamental grasses are commonly used plants in many home and commercial landscapes. These grasses are easy to establish and maintain, have few pest and disease problems, and make an excellent choice for sustainable landscapes in Louisiana.
Right now during the fall, ornamental grasses are in their prime. Many display strikingly gorgeous plumes. Starting to emerge in late summer well into late fall, these flowers have become trendy for their use in interior decorating. I have seen large bunches of pampas grass plumes sell for more than $60 on the internet. Why not invest in a plant that will provide beautiful cut flowers year after year so you can make your own arrangements?
Ornamental grasses are most commonly used in the landscape as screens and specimen plantings. They have a dramatic appearance, providing depth, texture and color. A grouping of plants of medium to large sizes can cover expansive areas, making an effective screen that provides privacy.
Ornamental grasses actively grow and produce blades (foliage) from spring through early summer. They produce plumes (flowers) in late summer through fall for a stunning display. In winter, they go dormant like our turfgrasses.
Plant ornamental grasses in well-drained soils in full sun for best growth and quality. The plants tolerate some shade, but more flowers will emerge with full sun exposure. Established plantings are very drought tolerant; they attract wildlife and have few pests with little to no maintenance.
Ornamental grasses have two growth habits. They are either spreading or clumping, with the clumping being less aggressive. Grasses vary in size and height, depending on the type. Some can reach up to 15 or more feet tall, such as pampas grass, while others stay more compact like the native muhly grasses.
You have a variety of colors, textures and sizes to choose from, and each species adds diversity and dimension to the landscape. Fertilization is seldom if ever needed, although a light application can be applied in the spring when new growth occurs and if soil tests indicate a deficiency. Cut back ornamental grasses just prior to new spring growth to remove dead blades.
Consider large plantings of ornamental grasses to stabilize soils and prevent erosion in places such as around ponds or hilly areas.
There are many types of ornamental grasses to choose from, and they can be a great addition to most landscapes. Some recommendations from retired LSU AgCenter extension specialist Allen Owings include reedgrass (Calamagrostis), weeping lovegrass (Eragrostis), maiden grass (Miscanthus), switchgrass (Pancium), fountaingrass (Pennisetum) and muhly grass (Muhlenbergia).
Maiden grass, fountaingrass, muhly grass and switchgrass are the most popular in Louisiana. Lemongrass (Cymbopogon citrates) has a wonderful lemon scent. It’s often found in herb gardens and is commonly used in Asian cuisine. Some of the maiden grasses are zebra grass, silver arrow grass and slender maiden grass.
Lovegrass is a low-growing, clumping grass that is often used for erosion control and low-maintenance landscape options for embankments. They produce white and red plumes from summer through fall.
Purple fountaingrass, such as the Louisiana Super Plant selection Fireworks, is a red-foliaged variety. It can be an annual in north Louisiana or a perennial in south Louisiana.
Grass plumes have become a trendy cut flower for interior design. Pampas grass plumes are one of the most popular. This grass is native to South American and grows very large, up to 15 feet in height and 10 feet wide. It can be aggressive in tropical climates such as those in coastal areas.
Pampas grass is easy to establish and is very hardy. Leaf blades typically grow 6 to 8 feet tall and are extremely sharp and can cut skin. The flower plumes are very large, growing 1 to 3 feet tall. They are silvery white and are very showy. Both male and female plants make plumes, with the females more impressive of the two.
These plumes make a great cut flower that can be dried and kept for quite some time if properly prepared. To cut the flowers to use in arrangements, follow these steps. Pampas grass leaf blades are sharp, so always wear long sleeves, long pants and work gloves to prevent cuts.
Harvest stems at midday after the dew has dried. Cut stalks of grass to the desired length. I recommend 3 feet of stem along with the plume. Remove all of the leaf blades. Gather the plumes in bunches and hang them up to dry for up to three weeks. Some dry on the plant as they age.
To help preserve the plumes and prevent the feather-light seeds from dispersing, spray them with a light coating of hairspray or floral protectant once they dry.
Before incorporating pampas grass into any landscape, you must consider the size of the area and give the plant plenty of room to grow. Also remember that the sharp blades of grass can be a mess to clean up in winter.
Mass plantings of pampas grass provide a great screen, and they are often used on golf courses (LSU golf course has large specimens) and along highways.
Grouped plantings of pampas grass make a great screen or windbreak. Photo by Sam des Bordes
Pampas grass can grow up to 15 feet tall and 10 feet wide. Photo by Sam des Bordes
Pink muhly grass. LSU AgCenter file photo by Allen Owings
Pampas grass plumes make great dry cut flowers for interior decor. Photo by Heather Kirk-Ballard/LSU AgCenter