Native Grasses for Ontario Gardens
| The ultimate guide to Ontarios’s most garden-worthy grasses |
Native grasses are crucial components of healthy gardens yet are often overlooked in favor of more showy flowers. In this article we will discuss the ecological and design benefits of using grasses in your garden and which ones are the best for landscaping. Click here to jump to the list of featured grasses.
The Benefits of Grasses in your Wildlife Garden
Host plants
In my opinion, the most over-looked benefit of growing native grasses in your wildlife garden is that they make great host plants! I notice that gardeners typically associate host plants with showy flowers such as Milkweed for Monarch butterflies or Pearly Everlasting for Painted Lady butterflies.
Just like these showy host plants, caterpillars and other insects have evolved special characteristics that allow them to eat the leaves of grasses.
For example, Bottlebrush Grass hosts caterpillars of the Northern Pearly Eye butterfly.
Little Bluestem hosts caterpillars of various Skipper species such as Indian Skippers and the Leonard’s skipper (Hesparia leonardus).
So, next time you are planning a butterfly garden, don’t forget the grasses - they are just as important as the flowers!
Natural bird feeders
Why buy bird seed when you can grow it? Most of our native birds eat seeds at one point or another in their lifecycle. Native grasses provide a bountiful source of seeds for birds. This is especially important over the fall and winter months when food is scarce.
Filling bird feeders can be an unpleasant and cold endeavor in the wintertime so why not supplement the wild birds’ diets with grass and enjoy watching them from the warmth of your house?
They key to feeding birds is to let your grasses stand over winter (no fall clean ups!) which leads into our next point…winter interest!
Winter garden interest
By leaving your grasses standing over winter, you will not only keep birds happy and healthy but you will create excellent winter interest in your garden. Many of Ontario’s native grasses will retain their structure well into the winter months.
The bronze colour of Little Bluestem contrasts against the snow and it’s fluffy seeds sparkle as they catch the low winter sun. The light beige colour of Switchgrass contrasts sharply with the darker brown seed heads of Hoary Vervain or Pale Purple Coneflower.
But winter interest should not be focused on the plants alone. You will also get to enjoy the presence of the birds who feast on the seeds.
Click here learn more about how to improve winter garden interest.
Reduce garden maintenance
Grasses and wildflowers are meant to grow together. Look around a natural prairie or meadow and won’t see one without the other. When we layer grasses and wildflowers together in the garden, we can create an interwoven matrix that resembles how these ecosystems are structured in the wild.
Mimicking natural ecosystems like this will help create a more resilient garden with reduced weed pressure.
Grasses also shade the ground in-between flowering perennials thus reducing evaporation and making your garden more resilient to drought. Many of our native grasses are very well adapted to dry conditions.
Wildlife Habitat
The layering of wildlflower’s and grasses, as mentioned above, also improves structure and diversity of your garden and therefore creates more opportunities for wildlife habitat creation. For example, tall grasses are an important part of fireflies habitat and you are more likely to see fireflies in areas with tall grass.
Despite being wind pollinated, grasses still support native bees. The exposed soil in between clumps of warm season grasses, such as Little Bluestem or Side-oats Grama, provides a perfect spot for ground nesting bees to make their homes. This is not possible in areas with mat-forming, cool season grasses such as those found in most hay fields.
Restoring Rare Ecosystems
A tallgrass prairie restoration with Indian Grass, Big Bluestem and Switchgrass
Native grasses are important for all the reasons mentioned above, but the key ecological reason to plant them is that they are critical components in one of Ontario’s rarest ecosystems - the tallgrass prairie.
Chances are that most people don’t relate Ontario to tallgrass prairie. However, tallgrass prairie was once found in scattered patches across Southern Ontario from Sarnia to Peterborough, covering roughly 1000 km2! Over the last few hundred years of European settlement, the majority of Ontario’s prairies have been lost to habitat destruction, mainly caused by urbanization and agriculture.
Now, as little as 1% remains!
As we loose ecosystems like the tallgrass prairie, we lose the wildlife that have come to depend on them.
The most dominant grasses of Ontarios tallgrass prairie are:
Big Bluestem (Andropogon gerardii)
Indian grass (Sorghastrum nutans)
Little bluestem (Schizachyrium scoparium),
Switch grass (Panicum virgatum)
Canada wild rye (Elymus canadensis)
By growing these grasses, especially in areas where tallgrass prairie once existed, you can help fix broken links in the food chain as many wildlife species benefit from grasses.
Using Grasses in your Garden:
For design purposes, native grasses can be divided into two categories:
Cool Season grasses are those that grow most actively during the cool weather of spring and fall, and go dormant in hot weather. The best time to plant, or sow seeds of, cool season grasses is in spring or fall. Bottlebrush grass and Junegrass are examples of cool season grasses.
Warm season grasses grow most actively during warm weather from late spring to late summer. They stay lush and green during the hot, dry weather of summer (right about the same time as your lawn is taking on that ugly, brown look). The best time to plant, or sow seeds of, warm season grasses is in late spring/early summer as the soil temperatures start to warm up. Most prairie species are warm-season including Little Bluestem and Indian Grass.
Typically, warm season grasses are the best choice for gardens as they are usually clump-forming and play very well with other plants. Non-clumping grasses that spread quickly by rhizomes can easily dominate your garden. A good example of this is non-native quack grass.
The amount of grass in your garden is also important. When planning your garden, you generally want to aim for a ratio of roughly 50% grass to 50% forbs (wildflowers). A ratio of 40% grass to 60% forbs works too. These ratios will allow enough grass to act as an effective ground-cover layer in-between flowers, thus suppressing weeds.
Too many grasses and flowers will be outcompeted.
Having a mix of cool and warm season grasses will further increase biodiversity and weed suppression.
The Best Native Grasses for Ontario Gardens:
So, what grasses are native to Ontario? There are many more than what are listed here but the following have been chosen based on their ornamental qualities, ecological value and commercial availability.
Big Bluestem & Goldenrod
Big Bluestem (Andropogon gerardii)
Height: 2m, 7ft
Exposure: Sun
Habitat: Prairies, meadows
Big Bluestem, known as muckode'kanes by the Anishinaabe, is a tall, warm season bunchgrass and is one of the defining grasses of the tallgrass prairie. It prefers moist to average sites but is drought tolerant once established. It’s fibrous root system can reach depths of 10ft!
Big Bluestem makes an excellent structural planting because of it’s tall, upright form and clumping habit. It is great for a privacy screen. It provides excellent winter interest in gardens because of it’s bronze colour and the fact that it stand upright for most of the winter.
Big Bluestem is best planted, or sown by seed, in late spring/early summer.
My favorite companion plants for Big Bluestem include Smooth Aster, Dense Blazing Star, or Woodland Sunflower.
The graceful growth habit of Sweetgrass (Anthoxanthum hirtum)
Sweetgrass (Anthoxanthum hirtum)
Height: 90cm, 3ft
Exposure: Sun, part shade
Habitat: Marshes, wet meadows
Sweet grass, known as wiingashk, -oon by the Anishinaabe, is a fragrant (smells like vanilla), low-growing, cool season grass. It spread by rhizomes and can be aggressive in moist conditions. It’s typical habitat is sunny, wet areas but it grows just as well in average moisture and light shade.
Sweetgrass is sacred to the Indigenous people of North America who burn it in ceremonies. It is also used for weaving baskets.
Use Sweetgrass as a fast-spreading groundcover by itself or among taller plants that it won’t outcompete. In fall, it turns attractive shades of yellow.
Sweetgrass grows harmoniously with Golden Alexanders and Canada Anemone. It pairs well with most wetland plants.
The arching stems and red flowers of Side-oats Grama (Bouteloua curtipendula)
Side-oats Grama (Bouteloua curtipendula)
Height: <90cm, 3ft
Exposure: Sun
Habitat: Prairies, sandy hills, open woods, fields.
Side-oats Grama is a small, warm-season clumping grass. It thrives in dry, well-draining soils with lots of sun. It tolerates a wide range of soils granted they are well-drained.
The tiny, but attractive, red flowers hang off arching stems in summer and look great when planted on mass. In the garden, it works well as a groundcover inbetween wildflowers especially if used in big clumps and drifts.
The oat-like seeds persist through winter, thus adding winter garden interest. While it is a clumping grass, it spreads slowly by rhizomes. It’s best planted in late spring and summer.
Side-Oats Grama is an excellent source of seeds and nesting material for birds. A number of Skipper species host on the foliage.
It doesn’t compete well with taller plants so pair it with compatible plants such as Butterfly Milkweed, Little Bluestem or Foxglove Beardtongue.
Canada Rye (Elymus canadensis) in a woodland edge garden.
Canada Rye (Elymus canadensis)
Height: up to 1.5m, 5ft
Exposure: Sun to shade
Habitat: Open woods, prairies, meadows, stream banks
Canada Rye is a cool season, clump-forming grass. It is very adaptable, growing in a variety of well-drained soils in full sun to part shade.
The droopy seed heads are very showy and add winter interest while feeding birds. When planted on mass, the seed heads are especially attractive as they blow in the wind. Canada Rye is best planted in spring or fall and is often used as a nurse crop in prairie restorations.
Canada Rye is a larval host for skippers and satyrs.
It pairs well with taller grasses and most meadow/prairie species. Note that it likes to self-seed but is not aggressive.
Bottlebrush Grass (Elymus Hystrix) seed heads
Bottlebrush Grass (Elymus Hystrix)
Height: 90cm, 3ft
Exposure: Dappled shade to part shade
Habitat: Forests, open woods, rocky woods
Bottlebrush grass is an upright, cool-season bunchgrass and is the most shade tolerant grass on this list. It is often found growing in rocky areas and slopes along the Niagara Escarpment. It can tolerate dry shade if there is a good amount of organic matter in the soil.
Bottlebrush Grass makes a nice structural grass in shade gardens. It greens up in early spring so it’s a good choice to add some early greenery to your garden. The spiky seed heads are very showy and look amazing when backlit by the sun.
Bottlebrush Grass hosts caterpillars of the Northern Pearly Eye butterfly. The seeds are eaten by birds.
Companions for Bottlebrush grass include other forest floor species such as Ferns, Large-leaf Aster, Bluestem Goldenrod or Wild Ginger.
Virginia Rye (Elymus virginicus)
Virginia Rye (Elymus virginicus)
Height: 1.2m, 4ft
Exposure: sun to part shade
Habitat: Wetlands, bottomland forests, stream banks
Virginia Rye is a cool-season bunch grass. It is similar to Canada Rye but is found in moister habitats and prefers fertile soils.
Its attractive seed heads persist into winter where they will feed birds and add winter interest. Its easily grown from seed and it best sown, or planted, in early spring or fall. Plant it in drifts inbetween other cool season plants.
Virginia Rye’s leaves are a larval host for skippers and satyrs.
As for companion plants, I have seen Virginia Rye growing in the wild with Canada Anemone, Blue Vervain, Joe-pye and Turtlehead.
Junegrass (Koeleria macrentha)
Junegrass (Koeleria macrantha)
Height: > 90cm, 3ft
Exposure: Sun
Habitat: Prairies, hillsides, sand dunes, open woods
June Grass is a cool season, clumping grass that is highly valued in natural garden design as it greens up in early spring with attractive blue-green foliage. It is usually found in dry, sandy areas but will adapt to most soils that are well-drained. It evens grows well in compacted soils, making it useful in ecological restoration.
Junegrass has especially high aesthetic value in early summer when its golden-brown seed heads provide contrast to the greens of surrounding warm-season grasses like Little Bluestem. Birds will eat the seeds.
Companion plants for Junegrass include Prairie Smoke, Nodding Onion, Wild Lupin, Butterfly Milkweed or warm-season grasses like Little Bluestem.
Switch Grass (Panicum virgatum) has a tall, upright stature.
Switch Grass (Panicum virgatum)
Height: 1.8m, 6ft
Exposure: Sun - light shade
Habitat: Prairies, meadows, open woods, shorelines
Switch Grass is a tall, warm season bunchgrass and one of the defining grasses of the tallgrass prairie. It tolerates a wide range of soils and moisture regimes but prefers medium to moist soils in full sun. In dry conditions it will grow shorter. It grows primarily in clumps but spreads slowly by rhizomes.
Switchgrass is prized in native gardens due to its elegant, vertical stature and attractive winter foliage. Due to this, it makes an excellent privacy screen. In mid-summer it is topped by pink-green flowers that give the plant an attractive, airy appearance.
In winter the leaves take on a beige colour that contrasts really nicely with the seed heads of wildflowers.
The seeds are an excellent food source for birds. Pair Switch Grass with Woodland Sunflower, Giant Purple Hyssop, Smooth Aster or even Pale Purple Coneflower.
The fluffy seed heads of Little Bluestem (Schizachyrium scoparium)
Little Bluestem (Schizachyrium scoparium)
Height: 90cm, 3ft
Exposure: Sun
Habitat: Shortgrass/tallgrass prairies, sandy shores, alvars
Little Bluestem is a warm season clumping grass and is one of the defining grasses of the tallgrass prairie. It prefers dry to medium, well drained soils and can tolerate a wide range of soil types. It may flop if you plant it in too much shade or rich soils.
Little Bluestem is valued in gardens for it’s blue-green foliage and drought tolerance. It will stay green through the toughest droughts. In fall it takes on an attractive bronze hue and sports fluffy seed heads. This is really an unbeatable ornamental grass for winter interest when planted on mass.
The foliage of Little Bluestem feeds a variety of Skipper species. The dried leaves are popular nesting materials for birds. The seeds are eaten by birds.
Companions for Little Bluestem are numerous. In really dry soils, try pairing it with Butterfly Milkweed, Slender Blazing Star and Nodding Onion.
The Blue-gray foliage of Indian Grass (Sorghastrum nutans)
Indian Grass (Sorghastrum nutans)
Height: 2m, 7ft
Exposure: Sun
Habitat: Prairies, meadows, open woods, fields
Indian Grass is a warm season clumping grass and is one of the defining grasses of the tallgrass prairie. It prefers dry to moist soils but it fairly adaptable to most well-draining soils. Expect it to grow shorter in drier soils.
Indian Grass is valued for it’s blue-gray foliage and tall, vertical stature which lends well to being used as a privacy screen. The showy fall colour takes on a bronze/orange hue. It persists into winter making it a suitable structural plant for winter interest. It has very showy seed heads.
The foliage feeds the larvae of various skipper species. Birds eat the seeds and use the dried parts for nesting material. The fact that it’s foliage persists into the winter months means it is good for creating shelter for wildlife.
Good companions for Indian Grass include Big Bluestem, Oxeye Sunflower, New England Aster or Wild Bergamot.
The airy seed heads of Prairie Dropseed (Sporobolus heterolepis)
Prairie Dropseed (Sporobolus heterolepis)
Height: 60cm, 2ft
Exposure: Sun
Habitat: Prairies
Prairie Dropseed is a warm season clumping grass. It prefers dry to average soils in full sun. It is adaptable to a variety of soil types and is very drought tolerant.
Prairie Dropseed is valued in gardens due to its elegant, mounding form and airy seedheads. It is slow growing and doesn’t tend to self-seed so it’s great for urban gardens. The seed heads are particularly attractive in the fall and winter where they take on a golden-bronze colour.
The seeds are a food source for birds. Try pairing it with prairie species like Butterfly Milkweed, New England Aster or Pale Coneflower.
Poverty Oat Grass (Danthonia spicata)
Height: 60cm, 2ft
Exposure: Sun, part sun
Habitat: Dry, upland woods; limestone bluffs; rocky or sandy slopes.
Poverty Oat Grass has yet to catch on in native plant nurseries and gardens, but has a lot to offer!
It is a cool season, clump forming grass with dense tufted foliage that greens up very early in the spring. It is very drought tolerant and will grow in nutrient poor, gravelly soil.
We love how compact and upright this grass is, making it good for tight spaces. It doesn’t spread aggressively but it does form a dense root system that will help mitigate erosion.
The dried foliage takes on a twisted, wiry form that will add unique and interesting textures to your landscape.
Note that it does not like being shaded by taller plants, so pair it with wildflowers like prairie smoke, Harebells, Upland White Goldenrod or Cutleaf Anemone.
The leaves host caterpillars of the Leonard’s skipper and Indian skipper. It is not very popular with deer or rabbits.
