by Emma Murphy, Master Gardener

Growing up in southwestern Ontario, I loved seeing these bluish star flowers in summer along roadsides. When we stopped to take a look, we were surprised to see them somehow growing out of straight gravel or other disturbed soil. Eventually, I found out they were Wild Chicory (Cichorium intybus), not native to Ontario. This plant is opportunistic and hardy, but incredibly hard to grow in a home garden (believe me, I tried, before I knew better). The root, roasted and ground, is used as a coffee substitute.

It’s interesting how many people assume that the Ontario roadside flowers they see out their car windows are native to our province – in fact, many are non-native opportunists from Europe or Asia that colonize quickly on disturbed sites or ditches and wetlands and outcompete native species, negatively affecting biodiversity and increasing habitat loss.

Here are some of the plants you may recognize from your travels – none of them are native to Ontario. Are you surprised?

Chicory (Cichorium intybus)
This plant grows everywhere, often in close proximity to Queen Anne’s Lace (see below), and the colour combination of white and blue is very pretty. Both the leaves and roots of chicory are used for culinary and medicinal purposes, and it’s also known for its use as a coffee substitute. More info HERE.

Dame’s Rocket (Hesperis matronalis)
From Europe, people also refer to this as spring phlox, but it’s not our true native spring wild blue phlox (Phlox divaricata) – as the ditty goes – Dame’s Rocket has 4 petals, while our native phlox has 5 petals. Dame’s Rocket also has ALTERNATE leaves and phlox has OPPOSITE leaves. It is a prolific self-seeder and fast-grower and thrives in roadsides, forest edges, and disturbed areas. More info HERE and HERE.

Common Dandelion (Taraxacum officinale)
Yes, the dandelions we see on the roadside (and in our lawns and gardens) are not native to Canada. While they show up early and provide some pollen, they definitely don’t support our native bees. More info HERE.

Creeping Bellflower (Campanula rapunculoides)
Introduced from Siberia, this pretty looking plant spreads aggressively in gardens and natural areas. As many gardeners know, once you have it, it’s really hard to get rid of the long, parsnip-like roots as even small root fragments can regrow. More info HERE and a Facebook support group HERE.

Red, White, and White Sweet Clovers (Trifolium repens, T. pratense, and Melilotus albus)
While Ontario has three native clovers – Purple Prairie Clover (Dalea purpurea), White Prairie Clover (Dalea candida) and Slender Bush-clover (Lespedeza virginica), the white, red, and sweet white clovers you see on the roadsides are likely to be non-native escapees from agricultural operations. The worst of these is sweet white clover. All are legumes, so they fix nitrogen in the soil. More info HERE.

Bird’s-foot Trefoil (Lotus corniculatus)
Brought to North America as a forage crop for animals and a green manure, this low growing plant with bright yellow flowers is now found along roadsides all over Ontario. Its name comes from the seed pods splayed in the shape of a bird’s foot. It’s attractive to bees and converts nitrogen, so it is often used in soil stabilization or rehabilitation projects. More info HERE.

Crown Vetch (Securigera varia)
In decades past, this dense, quickly spreading plant was used by highway department crews to stabilize new road cuts. Though it looks pretty with its pink flowers, it’s often grows wildly out of control. More info HERE.

Yellow and red hawkweed (Pilosella aurantiaca formerly Hieracium aurantiacum)
While very colourful, these are aggressive plants that can outcompete native species and form dense mats, reducing biodiversity and forage for wildlife. They are known to spread through seeds, stolons (aboveground stems), and rhizomes (below ground stems). More info HERE.

Oxeye Daisy (Leucanthemum vulgare)
This colourful white daisy resembles the English daisy but it not a true daisy, and is smaller than a Shasta daisy. The white petals are, in fact, discrete flowers. It’s the same with the yellow central disc, which is made up of hundreds of tiny individual flowers. It seeds profusely (I speak from experience) which makes it very hard to remove from your garden. More info HERE.

Queen’s Anne Lace/Wild Carrot (Daucus carota)
Native to Europe and Asia, it is a common roadside plant with white flowers and feathery leaves. If you crush the leaves of this familiar, flat-topped flower, which looks like a flurry of tiny snowflakes, and you will smell carrot. It’s a secondary Noxious Weed in Canada and appears on invasive lists in some US states. This is the species which developed into our domestic carrot, Daucus carota subsp. sativus. More info HERE.

Mullein (Verbascum thapsus)
Non-native mullein is easy to spot with its very distinctive appearance. About 2-3 ft tall (but can be taller), flowers appear on the top of the stalk, but it’s well-known in herbal medicine for use in coughs and skin irritations. While not typically a concern in cultivated agricultural land, it can be problematic in pastures and roadsides due to its ability to colonize disturbed soil. More info HERE.