Lynda Ellis, UM Extension Master Gardener in Anoka County.
With apologies to Walt Whitman, grass leaves (blades) are small in our lawn, but grow to prominence in the many ornamental grasses now available. They are low maintenance and deer-resistant, have few insect or disease problems, come in many different colors and heights, and often have attractive plumes. Let’s learn more about ornamental grasses.
A few of the many ornamental grasses and sedges are listed below. Except as noted, they are clump grasses, hardy in zone 4, and like full sun. Miscanthus, the most popular ornamental grass in the US, blooms in late summer and has prominent white plumes: Miscanthus sinensis ‘Variegatus’ is 4’ tall with showy, white foliage; ‘Purpurascens’, red flame miscanthus, is 4-5’ tall with red foliage; ‘Giganteus’, giant miscanthus, grows to 10’. Native little bluestem typically is 3’ tall and cultivar ‘Blue Heaven’ is 4’ tall. Both have excellent fall color and are a preferred plant for skipper butterflies. Another native, red switchgrass, blooms in late summer and is 4’-5’ tall. Native tufted hairgrass, 4.5’ tall, is one of the first to green up in the spring. It grows well in shade.
Other popular grasses in Minnesota are feather reed grass ‘Karl Foerster’, and newer cultivars ‘Overdam’ and ‘Avalanche’. They bloom in June on 4’ slim, upright stems. Fall blooming reed grass has pink to green flowers in September on 4’ stems. Blue oatgrass blooms in May on up to 5’ tall stems. It declines in the heat of summer and can be cut back then.
Ribbon grass is very showy, white with green stripes, non-clumping, about 3’ tall. It is spreads rapidly in full sun, less so in part shade. Purple fountaingrass is not hardy in Minnesota and is sold as an annual for containers or flower beds. It can handle part shade.
Sedges are grass-like plants that handle shade; all can tolerate wet feet and can be used in rain gardens or shoreline restoration. Their stems are triangular, not round as true grasses. Gray’s or mace sedge, 1-3’ high, has flowers that look like a medieval mace; fox sedge is 1-3’ high; palm sedge is 2-3’ high.
Grass clumps are usually planted in spring and are mature in 1-3 years. When planting, allow space for the clump to expand. In the early spring cut back to approximately 2”. After a few years you can divide clumps in the spring for more plants. They can be treated as any other perennial, with taller ones at the back of a garden, and smaller ones closer to the front.
When we think of “leaves of grass” our thoughts now can range from the 1/8” width of blades of Kentucky bluegrass to the 2” width of blades of the giant miscanthus. For more information, see: http://www.arboretum.umn.edu/ornamentalgrasscollection.aspx and http://www.friendsofeloisebutler.org/pages/seasonal/ornamentalgrass.html .