Threats to Plantings

Reed Canary Grass

Anyone who has battled an invasion of Reed Canary Grass knows it to be a formidable opponent. It is one of the most difficult invasive plants to control because it can quickly spread forming dense monotypic colonies that force out other grasses and plants.

Reed Canary Grass, Phalaris arundinacea, is native to Europe and Asia, and parts of North America. It is difficult to distinguish between the Eurasian and North American ecotype, but the Eurasian ecotype or possibly a cross between the Eurasian and native plants are considered to be more aggressive. This cool season grass was brought to this country in the 1830s. It was used for erosion control and forage and hay for animals.

Identification and life cycle: Reed Canary Grass is a course, large grass growing from 2 to 9 feet tall. Its tapering leaves – ¼ to ¾ inches wide - are flat and rough on both sides and the stems are sometimes hollow. It starts growing in early spring and blooms in May to mid-June. The seed-heads are purplish-green early and change to a beige color. The plant spreads by seeds and creeping rhizomes. The sod-forming, perennial grass likes wet, saturated soils although it will grow in dry upland areas and in partial shade. However it does not like to be in standing water for long periods of time. The grass can be found in wetlands, ditches, wet prairies and marshes, stream banks, and in disturbed areas.

Distribution: According to the USDA it is present in 43 states. Twenty states, including Illinois, Wisconsin, and Missouri, consider it an invasive species.

Problems/impacts: The rapidly spreading grass forces out other species reducing biodiversity and creating poor wildlife habitat. The U.S. Forest Service reports that the grass is invading forested areas resulting in a reduction in tree regeneration. It can be problematic in riparian buffers as it crowds out seedlings, and in wetlands, and bioretention structures where it can replace native plants.

Control: Like most invasive species the best control is through prevention – recognizing the beginning of an infestation and eliminating the grass. Eradication is difficult because of the extensive below-ground rhizomes and because the large seed banks present in the soil can re-emerge and re-colonize treated sites. A mix of management practices should be considered including mechanical (mowing, burning, removing soil containing seeds), manual (hand-pulling in small areas) or chemicals approved for use near aquatic areas.


(References)
Wisconsin Department of Natural Resources
USDA National Plant Data Center
USDA Forest Service
Aquatic Invasive Species
Invasive Plants: Guide to Identification and the Impacts and Control of Common North American Species by Sylvan Ramsey Kaufman and Wallace Kaufman