Not your average lawn grasses

Native grasses, sedges and rushes

Minden is located in the Haliburton Highlands, a region of some of the last intact forests of Southern Ontario. As you move northward in this region, the grasslands of Southern Ontario slowly give way to the great temperate forests of the north with many lakes. The depth of natural soils thins and the granite of the Canadian Shield emerges. Grasses, rushes and sedges are important plants in prairie, or grassland ecosystems, but are also found in natural woodland and waterfront landscapes too.

What’s the difference between a sedge, a grass and a rush? “Sedges have edges, rushes are round and grasses are hollow, right up from the ground.”

Why are these kinds of plants important to the Haliburton Highlands?

The varieties of native grasses are not as numerous as sedges in the Haliburton region but they can be found in woods and along shorelines and roadsides. Grasses generally like sunny open spaces and deep rich more alkaline soil. Sedges and rushes are far more numerous. The region is dominated by wetland habitat so it’s to be expected that edges of wetlands and shorelines are populated by moisture loving sedges and rushes.

There is a current craze for grasses that is a little concerning for our region. Many ornamental grasses from Asia and Europe such as the Miscanthus varieties and Phragmites are invasive in all parts of Ontario. But even certain grasses native to Southern Ontario should not be planted in zone 4 Haliburton County. With a longer growing season due to climate change some grasses from southern Ontario can now mature and produce fertile seed in our more northern region. Grasses like Big Bluestem (Andropogon gerardii) are now setting seed and expanding their habitat northward. The concern is that they may become invasive. There has been little study of the impact of these grasses in our region so we should plant with caution. Ornamental grasses native to Southern Ontario are readily available from garden centres and specialty nurseries, but they could be aggressive. The grasses native to our region are not aggressive. They aren’t easily available to purchase and would have to be started from locally sourced seed.

What steps can you take on your property for grasses, sedges and rushes?

In winter, birds feed on the seeds, so please don’t cut back your grasses or longer sedges until spring in order to leave the seed stalks for the birds. Like a few other plants, grasses provide interest in an otherwise empty winter garden. Native solitary bees are known to overwinter in the hollow stems of grasses and other plants so yet another reason to not over-tidy your garden in the fall.

In summer, the leaf clumps of native grasses, sedges and rushes provide shelter for ground nesting bees and other important insects.

Grasses rustle in the slightest breeze creating a full sensory garden experience. Grasses also look stunning in planters. Check out the article on container gardening on the Haliburton County Master Gardeners website https://www.haliburtonmastergardener.ca/resource/container-gardening-2/

Local horticulturist Belinda Gallagher happily discovered that growing grasses and tall stalked flowers together supported the flowers which on their own would topple over. The Woodland Sunflower (Helianthus divaricatus) found along the Riverwalk can grow to 6’ tall and like the False Sunflower (Heliopsis helianthoides) and Cup Plant (Silphium perfoliaum) are best planted with tall grasses to give support. She also advises not to fertilize these prairie plants. Excess fertilizer causes rapid growth and tall spindly plants prone to toppling and disease.

Grasses and sedges are wind pollinated and not interesting to bees for pollen but they are host plants for the caterpillar of many butterflies and moths.

Other plants at this tour stop include:

Strict Blue-eyed Grass (Sisyrinchium montanum) is actually not a grass! It is a member of the Iris family. It is a common native in the highlands. It likes dry or moist sandy soil and lots of sun.

Common Rush (Juncus effusus) is found at this tour stop. Rushes are wetland plants and must have their roots in very moist soil or in water. They are a key plant in wetlands, filtering and cleaning the water and helping to prevent soil erosion.

Sedges

Sedges are cool season plants and one of the earliest arrivals in spring, browning up a bit in mid summer but greening up again and looking great late into the fall. They come in all heights from 10 cm to over a meter tall, with variations in colour and leaf shape. Many of our native sedges like moist soil and sun to partial shade, but there are varieties that thrive in drier soils and would make an interesting alternative to turfgrass in many areas wet or dry. They pair well with taller plants as their grass-like leaves hide the stark leafless bases of taller plants. Like grasses, the seed heads of sedges and rushes are an important food source for birds and other animals. Many sedges bloom early in the spring which is very critical to those emerging insects looking for food. Its seeds are dispersed by ants feeding on its oily outer base, releasing the seed to germinate.

Grasses, sedges and rushes are superstars of soil conservation and restoration. Their various root systems and clumping growth habits allow them to filter water and help prevent erosion by retaining soil. They tolerate a range of soil conditions and return nutrients to the soil. Ask your local garden centre to stock sedges.

Long-stalked Sedge(Carex pedunculata) is a common clump forming woodland sedge found in sunny wooded openings. It can grow in regular moist soil.

Open areas around our homes are not the natural forested or wetland ecosystems of the highlands or its native soils. For practical and safety reasons large trees should be planted a minimum of 6 metres (20’) away from a building. So if it’s not practical or desirable to have a natural woodland close to the house, why not be creative and plant a sunny meadow made up of native plants from other naturally sunnier parts of Ontario and Canada. Start small, know your site conditions: light, soil type and depth and then set out to mimic one of the many prairie types. Nature North has some detailed information about various prairie types and how to establish a prairie or meadow suited to your conditions. Wildflower Farm in Coldwater ON sells seeds and will talk you through the growing process for optimal results. Another useful resource about the difference between a meadow and a grassland is available from Evergreen.

http://www.naturenorth.com/RCNP/RCNP.pdf

https://www.wildflowerfarm.com/

https://www.evergreen.ca/downloads/pdfs/

https://lorrainejohnson.ca/blog/suggested-sedges