The use of grasses as home landscape specimens is a recent phenomenon. When I started propagating North American plants almost twelve years ago, I never considered growing our local native grasses. I did not understand their role, therefore it was difficult for me to market their values. It is ironic we are surrounded by grasses everywhere in the landscape, yet the majority of us can name but a few. Grasses meet many landscaping needs, such as focal points, texture and colour.
Equally important and vital to growing native grasses is the fact that less than one per cent of original Ontario tall grass prairie exists today.
For design purposes, perennial grasses generally have four main growing characteristics:
•“Spreaders”: These are grasses that spread using underground roots.
•“Clumpers”: Most gardeners are happy with the clumping grasses, as they will stay in one spot when planted and do not invade the rest of the garden.
•Cool-season: Your lawn or turf is a cool-season grass that actively begins to grow as soon as temperatures are above freezing. The downside of a cool-season grass is that it tends to go dormant or turn brown during periods of drought and heat (typically mid July to mid August in Ontario).
•Warm-season: A warm-season grass begins its growth much later in the growing season anywhere from late spring to early summer. Warm-season grasses usually begin their season in Ontario between mid-May to mid-June, when soil temperatures reach 16 to 21 C (60 to 70 F). Their biggest benefit is that they are lush and green during those hot late-summer days.
Prairie grasses have extensive root systems. The heart and soul of a native grass is below the ground with grass/root proportions are nearly one-third top foliage and two-thirds roots. A typical prairie grass such as little bluestem grows about one-half to one metre tall, however its roots can stretch into the ground as much as up to three metres deep. Ontario prairie grasses are extremely drought tolerant once established. Generally, native prairie grasses only require average soil nutrients and the average local rainfall.
■Cool-season grasses give immediate height (early summer).
■Warm-season grasses reach mature heights over the duration of the growing season. Usually by mid to late August in an Ontario garden.
■If a plant tag lists the height of a grass as one-half to one metre tall (two to three feet), this generally means the foliage averages 0.3 to 0.6 metres (one to two feet). The seed or flower gives it that extra foot when in bloom.
■Grasses that spread are appropriate for embankments, erosion control, natural ponds and prairie/meadow gardens.
■All grasses provide food, cover and nesting material for our birds and other wildlife.
■It is a good idea to have a combination of cool- and warm-season grasses for natural diversity.
■Maintenance: Grasses only require an annual haircut in early springtime (April). Leave two-and-a-half to five centimetres at the base. Use the tops as mulch or spread them around the base of the planting area.
Easy to Grow Ontario Native Grasses
BIG BLUESTEM GRASS (Andropogon gerardii)
The “king” of native warm-season grasses. This long-lived clumping grass has nourished millions of bison. Its height and interesting, three-prong seed heads that resemble turkey feet make it a stunning attraction in the garden. Average soil and tolerates clay. Full sun. Height: 1.2 – 1.8 metres (four to six feet).
LITTLE BLUESTEM GRASS (Andropogon scoparium)
This beautiful warm-season prairie grass is clump-forming and offers bluish-green foliage. The spectacular reddish brown to copper fall colour provides interest in the garden amidst our long, cold winters and snowfalls. This to-die-for native grass is the most sought after ornamental grass for the home landscape. Average to dry soil. Full sun to part shade. Height: 0.6 – 0.9 metres (two to three feet).
CANADA WILD RYE (Elymus canadensis)
A cool-season bunch grass. The attractive arching seed heads make a great addition to fresh and dried floral arrangements. While outstanding in the prairie garden among the wildflowers, it is not suited to be presented by itself or as a focal point, as this wild rye tends to “flop down” after a hard rain or high winds. Medium to average soil. Full sun to part shade. Height: 0.6 – 1.2 metres (two to four feet).
VIRGINIA WILD RYE (Elymus virginicus)
This cool-season native is widely adapted throughout Canada and the United States. The straight, stiff and bristly seed heads are attractive in floral arrangements. Blooms in early summer and is often found in flood plains, thickets and prairie. Average to moist soil. Full sun to part shade. Height: 0.3 – 0.9 metres (one to three feet).
SWEETGRASS (Hierochloe odorata)
Aboriginals of the Great Plains believe this was the first plant to cover Mother Earth. It is a reminder to us to respect the earth and all the things it provides. The Odawa and Ojibwa Anishinabe believe it was a purifier and burned sweet grass before all ceremonies to enable them to communicate more clearly with the Great Spirit. Traditional aboriginals of the Six Nations use sweet grass in various crafts and basketry. It is extremely fragrant in its dried form. Moist, rich loam. Full sun. Height: 0.6 – 0.9 metres (two to three feet).
EASTERN BOTTLEBRUSH GRASS (Hystrix patula)
A unique clump-forming woodland native that offers a rather wide-bladed, dark green foliage. The very attractive seed heads resemble bottlebrushes and normally bloom during our Ontario summers. Seed heads are excellent specimens for dried arrangements. Medium to loam soil. Part to full shade. Height: 0.6 – 1.2 metres (two to four feet).
PANIC/SWITCH GRASS (Panicum virgatum)
This hardy, drought-tolerant, warm-season grass with its tiny, open seed heads is proving to be a favourite of the finches. The large, clumping foliage provides a full fountain appearance. Attracts birds and offers a beautiful fall show with its tan/copper blades. Average soil. Full sun to part shade. Height: 1.2 – 1.5 metres (four to five feet).
INDIAN GRASS (Sorghastrum nutans)
A handsome, robust, tall prairie grass that produces glossy, copper plume-like seed heads in late summer. While highly nutritious to cattle, the striking prairie native and state grass of Oklahoma is sure to attract many birds to the garden. Medium to dry soil. Full sun. Height: 1.2 – 1.8 metres (four to six feet).
CORD GRASS (Spartina pectinata)
Long ago, this cool-season prairie grass dominated the bottomlands of the Missouri River in pure stands. It is highly recommended for embankments, stabilization and low, wet sites. Cord grass is only for the large garden as spreads rather quickly and competes well with tall prairie wildflowers and native sunflowers. The large, showy seed heads attract many birds. Good and interesting fall colour. Aboriginals made cordage from the tough grassy blades. Average to moist soil. Full sun to part shade. Height: 1.2 – 2.7 metres (four to nine feet).
PLANTAIN-LEAVED SEDGE (Carex plantagenia)
The uncommonly wide leaves form impressive clumps in shaded or woodland settings. Naturally occurs in shady forested areas near oak stands. Once established, it can tolerate dry, shady locations. Seeds feed a variety of wildlife. Rich loam soil. Part shade to shade. Height: 0.3 – 0.9 metres (one to three feet).