Ornamental Grasses  Fact Sheet  Horticulture Services Division Capitol Gallery 600 Maryland Avenue SW, Suite 3300 Washington, DC  20024

GRASS GROWTH FORM All grasses have the same basic growth habits and internal structure.  They have a compressed stem called the culm at the base of the plant.  The culm is where growth originates in the grass.  It is protected by several layers of tissue.  The position and the extra protection of the growing tip is what allows grasses to be grazed, cut and mowed and still grow back.  The stems of grasses are always cylindrical and hollow, except at the nodes (the joints where the leaves are attached). One leaf is attached at each node, alternating from side to side up the stem.  Flowers:  One of the most interesting aspects of grasses are their flowers.  Grasses flower at many different times of the year.  Grasses are wind pollinated; therefore, the structure of their flowers is different from many other plants.  The individual reproductive parts are arranged in units called spikelets, which are equivalent to single flowers. The individual spikelets are arranged as an inflorescence, which is usually recognized as the grass “plume” or “wheat sheath.”   The spectacular floating plumes, panicles, and dangling oat-like spikes are striking in the landscape and add winter interest to the garden. Dispersal and Spreading of Grasses: Most grasses spread by seed and also by underground runners.  Turf grasses spread mainly by specialized underground structures, called rhizomes. Rhizomes are modified underground stems.  Some grasses that spread by underground stems form clumps, while others are called running grasses and continue to spread indefinitely.  The prolific seed producing ability and quickly spreading root systems of some grasses can cause them to become incredibly invasive.  It is important to select a grass for the landscape that meets the needs of the site. Spreading grasses are desirable for certain sites, while clump forming grasses are better for others.	WHY PLANT ORNAMENTAL GRASSES? Grasses can be used in the landscape just like perennials, but their usefulness extends far beyond that of a normal perennial.  Grasses are useful for erosion control, space barriers, wildlife shelters, winter interest, as a background to flowering plants, and as architectural features, to name a few.  Grasses add the dimensions of sound and movement to the garden as wind catches and rustles the leaves.  The dried stalks of many grasses remain upright for winter interest.  The wide variety of colors, sizes and growth habits of grasses assures that one will fit  almost any garden. Grass-Like Plants:  Often included in books with grasses are grass-like plants such as sedges (Carex), rushes and Liriope.  Many of these plants perform the same function in the landscape as ornamental grasses.  Some have slightly different maintenance requirements. BAMBOOS Bamboos are also grasses; they are made stiff by the presence of silica in their stems.  Often overlooked by homeowners, bamboos are a nice evergreen addition to the ornamental grass palette. The Giant Bamboo Forest in Asia is the endangered habitat of the Giant Pandas; however, there is a wide variety of smaller bamboos that are useful in a garden setting. Many bamboo plants are tender, but there are bamboos that are hardy in colder northern climates.  Some bamboos will die back to the ground in the winter, but will sprout anew in spring.  There are two types of bamboo:  running bamboo and clumping bamboo.  Running bamboos can be quite invasive; therefore it is important to plant them in an area in which they can be contained or where their running habit is an asset, not a detriment.  Clumping bamboos do not spread; they form clumps. Several bamboos have interesting shaped canes, or stems—there are golden bamboos and bamboos with zigzag canes.  Bamboos are usually evergreen and therefore provide good winter interest.
PLANT LISTS Commonly Used Grass Groups Calamogrostis, including feather reed grass Pennisetum, fountain grasses Panicum,  switch grasses Deschampsia, hair grasses Miscanthus, eulalia grasses Cortaderia, pampas grasses Andropogon, big bluestem Schizachyrium, little bluestem Festuca, fescue grasses Grasses for Prairie Restorations Andropogon gerardii, Big Bluestem Sorghastrum nutans, Indian Grass Andropogon scoparius,Little Bluestem Panicum virgatum, Switch Grass Spartina pectinata, Cord Grass Sporobolus heterolepsis, Prairie dropseed Bouteloua curtipendula, Side-oats grama Colorful Grasses Blue grasses:  Festuca glauca, Schizachyrium scoparium, Alopecurus alpinus, Sorghastrum nutans ‘Sioux blue,’  Red grasses:  Imperata cylindrica ‘Rubra’ (Japanese Blood Grass), Miscanthus sinensis ‘Purpurascens’  Variegated:  Arrhenatherum elatius bulbosum ‘Variegatum’ (Striped Bulbous Oat Grass),  Miscanthus sinensis ‘Cabaret,’ Phalaris arundinacea ‘Dwarf Garters’ Grasses for Wet Sites Arundo donax, Calamogrostis x acutiflora,  Miscanthus sinensis, Spartina pectinata, Cortaderia selloana Grasses for Shade Briza media, Arrhenatherum elatius bulbosum ‘Variegatum,’ Deschampsia caespitosa	GENERAL GRASS MAINTENANCE Ornamental grasses are a wonderful addition to your landscape because they require little gardening maintenance, and usually have few pest problems.  Selecting a proper grass for the growing site will reduce the amount of gardening maintenance needed.  The following is a list of some general maintenance tasks and growing conditions that many grasses, need: Well drained soil Very little fertilizer Proper space to grow and reach maximum size Some need staking to prevent them from falling over Removal of old growth in early spring  For Further Reading Darke, Rick.  Color Encyclopedia of Ornamental Grasses: Sedges, Rushes, Restios, Cat-Tails, and Selected Bamboos.  Portland:  Timber Press, 1999. Greenlee, John and Derek Fell.  The Encyclopedia of Ornamental Grasses:  How to Grow and Use over 250 Beautiful and Versatile Plants.  Rodale Press, 1992. Ottesen, Carole.  Ornamental Grasses:  The Amber Wave. New York:  McGraw-Hill, 1989. Taylor’s Guide to Ornamental Grasses.  Boston:  Houghton Mifflin, 1997.
Researched and written by Katie Elzer, 2000. HTML by Susan J. Pennington, 2000.