Invasive Plants

Invasive Plants

Garden Clippings for Feb 14, 2026

A few decades ago, Purple Loosestrife hit the news. The pretty perennial, with delightful rose-coloured flowers, began appearing in high numbers in Ontario wetlands, along roadsides, and in cultivated gardens.

Purple Loosestrife is believed to have entered North America from Europe and Asia around the turn of the century. Seeds and roots probably came with soil that was used as ballast in ships and dumped on this side of the Atlantic.

For many years Loosestrife posed no problem, but in the 70’s and 80’s conservationists rang the alarm bells because the weed began invading wetlands, preventing native plants from thriving. This posed a problem for wildlife that depended on the original native plants as a food source.

A solution was found in 1992. Two predator leaf-eating beetles were introduced from Europe whose job was to curb the growth of Loosestrife. A wise move, because wetlands have been largely restored to their original state.

We need a similar solution for Phragmites.

Nobody knows exactly how Phragmites came to North America, but its arrival was inevitable, given the amount of trade that occurs between nations. Phragmites’ growth is so aggressive that it now ranks on the top of the Canada’s and Ontario’s Invasive plant list.

The Great Lakes region has been particularly hard hit by Phragmites. Many ditches, ponds, beaches and wetland sites are now covered with Phragmites. The weed is highly adaptable, and is now invading conservation areas, highway medians and natural meadows.

Phragmites is easy to identify with its tall grassy stems growing up to 4 metres. A silvery plum appears in fall. By winter, stems become straw coloured and by the end of winter most dry stems are on the ground, creating a dense mat of foliage that smothers the desirable original plant life. In spring when soil warms up, new sprouts appear and quickly grow to 3 or 4 metres high.

Eradicating Phragmites is no easy task. Professionals use machines to trample growth followed by an application of herbicide to young plants. Homeowners who find Phragmites in their yard are encouraged to dig out seedlings as they sprout. Avoid adding Phragmites roots and stems to the compost bin but place the plant in plastic garbage bags for proper landfill disposal.