Grow Your Invasive Species Knowledge

We can’t see them now but lurking beneath the snow are invasive plants. Next week is Invasive Species Awareness Week. It’s the perfect time to learn more about these pesky plants so you can avoid planting them in your garden come spring.

Invasive species are non-native plant, animal or pest species that outcompete native species for resources and dominate space. They provide less habitat for our native wildlife and have ecological and economic impacts.

You may have heard about dog-strangling vine or garlic mustard but invasive flowers, grasses and shrubs are often unknowingly planted in gardens.

Here are four lesser-known invasive plants with beautiful native plant alternatives:

Winged euonymus (Euonymus alatus)

Green leaves

Winged euonymus, also called burning bush, is a shrub native to Northern Asia. First introduced to North America in the 1860s, it has since spread into southern Ontario. Often planted in hedges and plant beds, it’s also found along highways and in natural areas throughout the Credit River Watershed.

Winged euonymus can grow in a variety of soil and light conditions. As a fast-growing plant, it can grow two and half meters high. The dark green, tear-shaped leaves turn bright red in fall.

Downy serviceberry is a great native alternative.

Oriental bittersweet (Celastrus orbiculatus)

Green leaves

Oriental bittersweet is a vine native to China, Korea and Japan. As a shade-tolerant plant, it grows in forests and woodland edges but can also grow in full sun in grasslands and along roadsides. There are isolated patches of oriental bittersweet throughout the Credit River Watershed.

Oriental bittersweet grows by wrapping around shrubs and trees. Its glossy leaves are rounded with finely toothed edges. This aggressive plant quickly takes over and can even kill large trees.

Attractive greenish yellow flowers bloom from May to June and create orange berries in fall. Birds help spread their seeds when they eat the fruit.

Yellow and red berries

Virgins bower is a great native alternative.

Japanese silver grass (Miscanthus sinensis)

Silver grass

Japanese silver grass, also called Chinese silver grass, was brought to North America as an ornamental grass. Like many ornamental plants introduced from overseas, it has moved into natural areas.

It grows one to two metres tall in dense clumps with long, thin arching stems that give it a fountain-like appearance. Flower heads look feathery and bloom from August to October.

Japanese silver grass grows quickly in a variety of soil types, from sand to heavy clay, allowing it to outcompete native species for nutrients and water. Try native grass alternatives like switchgrass and big-blue-stem in your garden.

Wild chervil (Anthriscus sylvestris)

Flower with tiny white petals

Wild chervil is a popular plant found in European wildflower mixes that have made their way to North America.

Wild chervil is in the parsley family. It grows 30 centimetres to 1.2 metres tall, but on occasion can grow almost two metres tall. Small white florets bloom at the top of the stem. The seeds are green and turn a shiny dark brown as they mature.

Black-eyed Susan is a great native alternative.

You can find alternatives to invasive plants to add colour, beauty and interests to you garden in our Guide to Gardening Wisely. Enjoy the many benefits of native plants in your garden from creating habitat for beneficial insects like bees and butterflies and other wildlife that depend on them.

Between February 22 to 26, follow us on Facebook and Twitter to learn more about how you can help stop the spread of invasive species during #InvSpWk .

Managing the Impacts of Invasive Species We are continuing our work on the Emerald Ash Borer Restoration Project at Rattray Marsh Conservation Area. Ash trees have been devastated by emerald ash borer (EAB), an invasive insect. From February 22 to March 13, restoration staff will be removing dead standing ash trees in priority sections of the forest.

By Kimberley Laird, Associate, Marketing and Communications

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