Ornamental grasses are an important component of our landscape. Whether planted in mass, forming waves or drifts, sprinkled among herbaceous beds and borders, or as single specimens, grasses add texture, color, and motion to every landscape. Laying back on a breezy summer and fall day just listening to the rustle of leaves as the wind moves through their leaves is one of the more pleasing sounds one encounters in the natural world. As grasses combine naturally with broad-leaf plants in prairies, savannas, pampas, velds, steppes, and meadows throughout the world, so are they essential in designed landscapes. This image is so imprinted in our mind, that a landscape without grasses and grass-like plants appears lacking. When dancing in our Panhandle wind or rhythmically swaying with a gentle breeze, the incorporation of grasses into the home landscape infuses the design with soothing images of nature, whether the style is formal or informal.
Ornamental grasses are clumping forming grasses called bunchgrasses, rather than turf or sod forming grasses, grasses that run. Many ornamental grass species can be used in beds or borders as accent or focal point to provide structure, separation and contrast, for line, form and seasonal interest in an unlimited number of designs and styles. In the fall when sunlight shines lower in the sky, back-lit plumes of ornamental grasses are particularly stunning. Additionally, ornamental grasses are useful for land reclamation in difficult alkaline and saline soils and for erosion control. Be mindful of any grass that increases by stolons and rhizomes--your flower bed is not the best location. As with any plant, match the grass to its purpose and location.
Warm and Cool Season Grasses
Grasses are divided into two categories, cool and warm season grasses. Cool season grasses green up as soon as the temperatures rise above freezing and are the first to bloom, usually in June. Warm season grass wait until the weather warms to begin to green up, as late as April and May, depending on the spring. Growth accelerates in the summer and blooms in late summer and early fall.
Grasses are also classified into C3 and C4 plants. C4 plants are more efficient than C3 plants at taking up atmospheric carbon dioxide and converting it into the starches and sugars vital to plant growth. ( C3 and C4 refer to the number of carbon atoms in the first molecular product of photosynthesis.) Generally, C3 plants are woody plants, annuals and cool season grasses. C3 plants use carbon dioxide directly from the air in photosynthesis, represent nearly 95% of the Earth's plant biomass and loose up to 97% of the water they take up from the roots to transpiration. C4 plants takes in carbon dioxide during the night and uses it during the day, similar, but not the same, as succulents (which use the CAM process to photosynthesize, uses roughly 12% of water that C3 plants use ). A C4 plant is more adapted to environments with higher temperatures (averaging at and above 86ºF), drought conditions (using 40-55% of water that C3 plants use) and lower CO2 concentrations than are C3 plants. Forty six percent of grass species are C4 grasses; C4 grasses require less water. (NSW Department of Primary Industries and Crop Agriculture Review).
A Grass to Ornament any Micro-niche
With over 11,000 species of grass to choose from, there are ample grass selections for every soil, and micro-niche in any size, shape, height, texture and color to fit your need and desire. Small tufted grass to tall bamboo or reed like grasses in tawny tans, metallic blues, rusty reds, amber yellows, dark as black to nearly white, solid, striped and variegated grasses are available with a little researching.
Grasses provide interest throughout the four seasons. Combining cool and warm season grasses, from spring through winter, grasses are a presence in the landscape. It is hard to beat the warm colors and intricate textures grass add in fall, and especially winter.
Native grasses are an important habitat plant, providing food and shelter to large and small animals, insects and birds. Many animals find shelter from predators; increasing the species diversity in any area. Many provide nutritional grazing and forage.
Few Maintenance Requirements
For all the benefits grasses offer, they seek precious little in return. Grasses are for the most part, disease and pest free, especially when placed in a location that meets their needs. Many ornamental grass species do not require supplemental irrigation, especially warm season grasses native to the western half of the U.S. Grasses native to riparian areas require more. However, many grasses are quite versatile, adjusting their growth depending on the water received each year.
By far, grass is a sun requiring plant. Most warm season grasses do better in part sun and full sun locations, with cool season grasses preferring afternoon shade in our climate. Grasses grown in shady locations will exhibit less flowering and pluming depending on the amount of shade/sunlight received.
Maintenance requirements for ornamental grasses are quite low. Once established (which usually occurs quickly for native grasses), grass roots grow deep and wide. Studies have shown that roots of grasses grow deep about twice the height of the grass (including flower stalk). In late winter (late February, early March), cut off last year's grown to about 2-3 inches of ground level and compost these leaves or use in vegetable gardens.
There are a few evergreen grasses used in home landscapes -- those should not be cut off. Lightly rake out dried and spent stems.
Remove any dead growth that could form in the center of the clump, or even the outside of the clump. Clump forming or bunch grass can be divided in late winter through early spring, while the grass is dormant (not yet greening up and growing). Simply slice through, dividing the root ball in half, thirds or quarters, depending on the size of the clump, and transplant or share with friends. Dividing and transplanting grass once it begins to grow is much riskier.
Because the roots of grasses grow deep, they are able to bring up nutrients that broadleaf plants can't. Warm season, drought tolerant grasses require minimum replenishment of organic matter. Medium and high water-use grasses benefit from an annual addition of an inch or two of compost in the bed, either spring or fall. Then just sit back in your lounger and listen to the wind.
A Few Favorite Ornamental Grasses for the Home Landscape
Bouteloua gracilis, Blue gramagrass. Perennial, drought tolerant, warm season sod forming grass of mid height; a dominant grass of the short grass prairie. Can be used with buffalograss for turf grass. Germinates quicker than buffalograss, usually in 5-7 days. In areas of heat and drought, it can be clump forming, rather than sod forming. Mow to 4 inches high. Do not water excessively, can survive quite well on our rainfall. Eyelet seed head.
Calamagrostis arundinacea, 'Karl Foerster' Karl Foerster Reed Grass. Cool season perennial bunch grass. One of the most erect ornamental grass, up to 3 ft, with plumes to 5 ft. One of the first ornamental grasses to plume out. Average garden soil with low to medium water. Will perform better with supplemental watering.
Calamagrostis brachytricha, Korean Feather Reed Grass, Clump forming warm season grass native to Asia. Prefers moister conditions and clay soil. Attractive with pinkish flower plumes to 4 feet, green foliage to 2'.
Chasmanthium latifolium, inland sea oats grass or wild oats grass. The clumping, upright, vivid green bamboo- like foliage grows from 2-4 feet. The seeds turns a copper to tan color in late summer. The showy green flowers dangle or hang from the side like earrings. Prefers shade and part shade and will grow in moist soils (and drier soils), attracts birds, attracts butterflies, serve as hosts for butterfly larvae, naturalizing, will make a nice cut or dried flower. If planted in sun, the foliage tends to yellow, but has a nice green color in shade. Could be invasive under moist conditions. Native habitat is shaded slopes; low thickets; stream banks.
Miscanthus sinensis 'Gracillimus', Maiden hair grass. Warm season clump forming perennial grass, grows to 5-6' tall. Plumes are white in late summer, very attractive. Medium water use. Many other varieties available. Non-native. 'Strictus' is an upright maiden grass with striped leaves – stunning!
Muhlenbergia lindheimeri, Lindheimers muhly grass. Tall, from 2-5 ft., warm season perennial bunchgrass, native to the Edwards Plateau of Texas. Will grow in clay, sand, caliche and loam soil. Do not cut back in spring. Cold hardy zone 7 - 11. Different varieties available.
Muhlenbergia capillaris ‘Regal Mist’, Texas native, cold hardy to at least Zone 7 (I’ve had several for 3 winters now),leaves up to about 12 inches and plumes 3' tall. Very attractive rosy pink plumes in late summer.
Nassella tenuissima, Silky thread grass, 18' x 12', soft textured perennial bunchgrass, Texas native grass, quite cold hardy. Flows nicely in the wind. Drought and heat tolerant. Spreads by seeds some. Can be a nuisance in moist circumstances.
Panicum virgatum 'Prairie Sky', Prairie Sky switch grass, 4-5' tall x 2 feet wide. Tall grass prairie native perennial warm season bunch grass. Quite versatile, will grow in many soil types and moisture conditions. Attractive blue-green foliage, nearly blue leaves. Mid summer blooming. A number of other selections are available, including 'Shenandoah'.
Pennisetum alopecuroides, Chinese Fountain Grass. Cold hardy clumping ornamental grass, up to 4' tall and 2 feet wide. Attractive bottlebrush or caterpillar shaped plumes in summer. A number of other pennisetums are grown, even the non-cold hardy Purple Fountain Grass that is often replanted each summer -- a good container grass. 'Hameln' is a fine variety to use.
Pennisetum purpureum 'Princess'. Broad burgundy leaves over 1 inch wide up to 3 ft tall, a petite form of P. purpureum 'Rubrum' and 'Prince'. Princess is dwarf, purple-foliaged napiergrass. Warm season clumping grass, a vigorous grower, said to be non flowering – mainly used as an annual ornamental grass, not cold hardy. Burgundy foliage that grows deeper in the sun and heat. Cold hardy to Zone 8.
Pennisetum setaceum 'Atrosanguineum' Purple fountain grass. Warm season clumping grass native to tropical Africa and southwestern Asia and Arabia – mainly used as an annual ornamental grass in a container in this garden. Burgundy foliage with soft reddish purple flower plumes. Variety P. setaceum 'Rubrum's' leaves are more reddish-purple. Not cold hardy.
Schizachyrium scoparium ’The Blues’, or 'Prairie Blues' little bluestem grass 2' x 15" wide. Shortgrass native warm season bunchgrass through out much of North America. 'The Blues' is an attractive blue selection. Also available in the nursery trade is 'Blaze' with striking fall red foliage. Little bluestem is suitable for a wide range of beds and borders.
Sorghastrum nutans, 'La Cueva Selection'. Le Cueva Indiangrass. Native to tallgrass prairies, grows to 4-5' tall and 15-18" wide. Warm season perennial grass adaptable to most soils. Low and medium water-use.
Sporobolus airoides, Alkali sacaton. Native perennial warm season tufted grass. Airy seed panicles stand tall above the leaves. Will grow in clay, alkaline and saline soils as well as silty loam. Heat and drought tolerant.
Sporobolus wrightii, Giant sacaton grass, warm season grass, 5-6' x 3', tolerates clay and saline soils very well. Very large, needs little or no supplemental irrigation. Very heat tolerant.
Angie Hanna, September 25, 2013