Gardening Articles: Flowers :: Perennials
by Jim Knopf
It's right that Americans love grasses. The extent to which grassy plains once stretched across the country -- from Denver east almost to the Appalachians -- stuns the mind. One of the great natural endowments of this land, these grass plains are now devoted mostly to other kinds of grass, corn in particular.
If this natural-looking sweep of grass is something you'd like to incorporate into your landscape, consider planting a section to native meadow grasses and flowers. More like gardens than lawns, these meadows or mini-prairies are usually restorations of the grasses and flowers that grow naturally in the area (or close approximations of that ideal), made for viewing, walking through and enjoying. These plantings are quite dynamic, especially in the first few years. And they require far less weekly attention than the traditional manicured lawn.
American meadow grasses are grouped by height: tallgrass, midgrass and shortgrass. Native to the Midwest and mountain states, any of these are worthy of serious consideration for planting in these sites. In other regions, these grassland types can serve as models for planting other, more locally adapted species. The height is important for the visual impact as well as the uses of the meadow area. It's easier, for example, to walk around on a shortgrass meadow than on a mid- or tallgrass meadow, and it is easier to see across a short or midgrass meadow than a tallgrass type.
Before planting your meadow, it's well worth taking the time to till the area, water it, wait for weed seeds to germinate, then till again. Tilling under the undesirable species will eliminate most of the troublesome plants. For really difficult perennial species like smooth brome (Bromus inermis) and Canada thistle (Cirsium arvense), however, it may be necessary to consider an herbicide like Roundup. A bit of pioneering spirit and some perseverance helpful, too -- meadow landscaping is much less familar to most gardeners than traditional lawnscaping."
Shortgrass meadows tend to grow ankle-high or lower and are the predominant grasslands of the western high plains, where the Rocky Mountains rain shadow results in the driest conditions on the Great Plains.
Dominant grasses of these regions are buffalograss (Buchloe dactyloides) and blue grama (Bouteloua gracilis). Buffalograss is a vigorous, spreading grass that chokes out many wildflowers. On the other hand, blue grama grows in non-spreading tufts so is much less competitive with wildflowers. In order to successfully incorporate wildflowers into a shortgrass meadow, either plant the entire meadow area with blue grama or plant only blue grama where wildflowers are desired.
A few of the most reliable flowers to plant in shortgrass meadows include chocolate glower (Berlandiera lyrata), dotted gayfeather (Liatris punctata) and poppy mallow (Callirhoe involucrata).
Shortgrass meadows grow best on very warm, dry sites. In Colorado, elevations above 6,000 feet are usually too cool and moist to remain pure blue grama and buffalograss, and tend to evolve toward midgrass meadows.
These meadows need occasional mowing, particularly during their first season, to keep cool-season grasses and broad-leaved weeds from growing too tall during cool, wet periods.
Midgrass meadows grow knee- to waist-high, often in or near ponderosa pines, and on the Great Plains between the eastern tallgrass and western shortgrass prairies. The natural precipitation in these areas is between that of the drier shortgrass and the wetter tallgrass regions. Midgrass meadow areas are common along the Front Range of the Colorado Rockies. Boulder, for example, has many areas of this grassland type extending from the mountain backdrop into residential areas. Midgrass meadows often continue indefinitely without mowing or burning. How specific maintenance depends on the site.
Dominant grasses include little bluestem (Andropogon scoparius), sideoats grama (Bouteloua curtipendula) and western wheatgrass (Agropyron smithii). Little bluestem and sideoats grama are bunchgrasses that won't spread and crowd out wildflowers. Western wheatgrass forms stands that are thin enough that many wildflowers can compete successfully.
Other useful grass species include bluebunch wheatgrass (Agropyron spicatum, syn. Elymus spicatus). This attractive grass is often difficult to establish, however. Crested wheatgrass (Agropyron cristatum) is a Eurasian introduction, but is perhaps the easiest midgrass to establish. It usually creates the appearance of the midgrass meadows faster than the native species. This bunchgrass doesn't self-seed significantly, so won't invade surrounding areas.
Attractive flowers to add to your midgrass meadow include gaillardia (Gaillardia aristata), Lewis' flax (Linum perenne var. lewisii) and Mexican hat coneflower (Ratibida columnifera).
There is some fire danger from the ponderosa pines, junipers and pi-on pines that may grow in this grassland. The grasses contain little fuel, but can carry a fire to the trees and shrubs. In dry conditions, mowing defensible" space adjacent to buildings creates very effective fire breaks. Removing lower limbs on ponderosa pines, and maintaining a reasonable distance between buildings and the woody plants are good tactics as well.
Tallgrass meadows grow from waist- to more than shoulder-high. These grasslands occur commonly on the eastern Great Plains, where precipitation is relatively high. Tallgrass areas also occur in floodplains and irrigated areas farther west. Tallgrass areas are wetter, so they are more likely to require periodic mowing or burning to keep woody shrubs and trees from taking over.
The dominant grass species include big bluestem (Andropogon gerardii), Indian grass (Sorghastrum nutans) and switchgrass (Panicum virgatum). These three grasses each develop strikingly beautiful fall colors. Examples of flowers that combine well with these tallgrass types are Maximilian's sunflower (Helianathus maximiliani), monarda (Monarda fistulosa) and purple coneflower (Echinacea purpurea).
There are several tallgrass preserves on the Great Plains that are worth visiting. At the University of Wisconsin in Madison, prairie restoration work dates back to the 1930s. The Morton Arboretum in Illinois has been working on prairie restoration since the early 1960s, and the center of the proton accelerator ring at the Fermi Laboratory in Illinois is a 650-acre prairie. One of the most striking examples of modern tallgrass landscaping is at a General Electric headquarters facility in Milwaukee, Wisconsin.
Adding wildflowers I advise clients to wait until the second year before planting wildflowers. Mowing the first year controls weeds while the grasses become established, but also eliminates desirable wildflowers. Leave patches of meadow free of competing grass for wildflower seeds or transplants. The flowers will eventually naturalize if they are well adapted. Blue flax (Linum perenne) is one wildflower that competes well when sown with grasses.
Optimum planting time for wildflowers is short. Many wildflower species need to be planted in early spring or be exposed to simulated winter in your refrigerator. Fall planting is risky, because the seed is vulnerable to wind and water erosion for such a long time.