Don’t Rush Out to Buy This Plant!

Flowering Rush is an attractive water garden plant that is considered invasive in Manitoba, but still sold in garden centers and on the Internet.

Flowering rush (Butomus umbellatus), a perennial aquatic plant native to Eurasia, was brought to North America in the late 1800’s for ornamental water gardens.   The first observations of this plant in Canada are from Montreal (ca. 1897) along the banks of the St. Lawrence.  Since that time it has quickly spread to naturalize wetlands, sedge meadows, streams, river banks, ditches, and lake shores from Nova Scotia to British Columbia.  It can be found growing in wet soil, shallow water, or under water.  In Manitoba, it has been observed at Patricia Beach, near Lockport, and along the Assiniboine River in Winnipeg.  The Invasive Species Council of Manitoba would like to find out locations of this plant across Manitoba.

Biology: Flowering rush grows and spreads primarily from thick, creeping rhizomes, and lesser through seed production.  Rhizomes also produce many small tubers (bulblets) that can break off to form new plants and follow water currents to infest new areas.  This plant is easiest to identify when it produces characteristic umbrella-shaped clusters of upright flowers.  Flowers are deep pink to white in color, 2 to 3 cm across, and on stalks.  Stems are 0.5 to 1.5 m tall and resemble bulrushes.  Leaves are on opposite sides of the stem, triangular with smooth edges and around 1 m long. 

Impacts: Flowering rush tends to colonize areas where new land is exposed as a result of lower water levels.  It grows aggressively, displaces native vegetation through its thick root system, and reduces biological diversity.  In areas of dense infestation, it can clog irrigation canals and interfere with boating and other recreational activities

Control/Prevention: Flowering rush is still widely available for purchase in garden centers and on the internet as a water garden plant.  The best method to control this invasive plant is to not buy it and plant it.  Removing Flowering rush by the roots is almost impossible without breakage or leaving fragments behind that form new plants.  Cutting below the water surface will not kill the plant, but will limit its abundance and nuisance.  Repeated cutting may also weaken the plant over time.  Removing all plant pieces is necessary to limit spread and should be dried and composted completely, away from water or wet areas.  Discarded plants should be burned or double bagged in garbage bags. 

Information: To report a sighting of this plant or to find out information on other aquatic invasive species, please visit www.invasivespeciesmanitoba.com.  Sign up for a free quarterly newsletter “Unwanted Invaders” produced by the Invasive Species Council of Manitoba at This e-mail address is being protected from spambots. You need JavaScript enabled to view it or phone (204) 232-6021.

Photo credits: plant, C. Fisher; flower, Washington State Noxious Weed Control Board.

HIMALAYAN BALSAM (IMPATIENS GLANDULIFERA):

Did you know this plant is considered invasive in Manitoba?

Originally from India and the western Himalayas, this attractive orchid-like plant (also known as Policeman’s helmet, Indian balsam, and Poor Man’s orchid) was introduced as an ornamental to many parts of Europe, New Zealand and North America.  It has escaped cultivation to invade natural areas in these regions.  In Canada, Himalayan balsam is found in eight provinces: British Columbia, Manitoba, Ontario, Quebec, Nova Scotia, New Brunswick, Prince Edward Island and Newfoundland.  Locally, it is found growing in some gardens and on two river bank areas in Winnipeg.  ISCM hopes to stop the spread of this plant through volunteer reporting and removal.

Himalayan balsam is an annual succulent herb with stems that are smooth, reddish-colored and hollow.  Plants can grow up to three meters (10 ft) tall.  Leaves are opposite or whorled, red-toothed, and occur in pairs or threes.  Flowers are small, pink to purple in color, and shaped like an English policeman’s helmet (which describes another common name given).  Himalayan balsam is capable of producing 800 seeds in pods which explode when ripe and eject their seeds up to five meters.  Seeds will float and quickly be transported along waterways to infest new areas.  Gardeners often pass on the seed to friends due to its ornamental beauty.

Himalayan balsam will grow in agricultural areas, natural forests, disturbed areas, rangelands, riverbanks, wetlands, and gardens.  In areas of introduction there are no natural enemies (e.g. disease, predators or competition) to keep this plant in check, and it will aggressively grow and spread.  Dense stands of Himalayan balsam can form which prevent establishment of native plants, make stream banks vulnerable to erosion when the shallow-rooted plants die back, and reduce overall biodiversity and ecological value of the land.   

To prevent the spread of Himalayan balsam, the Invasive Species Council of Manitoba encourages Manitobans not to purchase, sell, plant, or exchange seeds of this known invasive plant.  Please remove flowers before seed set and report sightings of this plant to ISCM to assist with its control.  For more information please contact us at (204) 232-6021 or This e-mail address is being protected from spambots. You need JavaScript enabled to view it . Visit our website at www.invasivespeciesmanitoba.com for a “What Not to Plant” list for gardeners.

PHOTO CREDITS:

• Himalayan balsam flower. Photo credit: Jan Samanek, State Phytosanitary Administration, Bugwood.org
• Himalayan balsam stem. Photo Credit: Michael Shephard, USDA Forest Service, Bugwood.org.
• Himalayan balsam infestation. Photo courtesy of Smithsonian Institute, Richard A. Howard Photograph Collection.

Cottager’s Awareness: Be on the Lookout for Aquatic Invasive Species in Manitoba This Summer

As another cottage season rolls around in Manitoba, it is a good time for the public to be reminded of aquatic invasive species (AIS) threatening our local waterways- wetlands, creeks, rivers and lakes.  A number of aquatic invaders have already been reported over the past few years (e.g. Rusty crayfish), while others are knocking on Manitoba’s doorstep.  Invasive species are non-native plants, animals and pathogens which were accidentally or intentionally introduced into habitats outside of their native range.  Their introduction and spread has caused harmful effects on the environment, society, economy, and even human health.  Invasive species are also listed as a major cause of biodiversity loss, and alteration and degradation of habitat for native species.  The United Nations has proclaimed 2010 as the International Year of Biodiversity, thus it is important more than ever to recognize the serious threat which aquatic invasive species pose to Manitoba’s landscape.

Aquatic invasive species are a problem because they aggressively grow and reproduce in and around water bodies.  Since these species are living outside their native range, they have no natural enemies (e.g. predators, competition, parasites or disease) to keep their population in check.  They can clog boat engines and cottage water intake lines, choke lakes and waterways, restrict use by boaters and swimmers, reduce native aquatic species (zooplankton, waterfowl, clams, etc), including sport fish, foul fishing gear, degrade the natural beauty of our lakes and waterways, and reduce waterfront property value.  They can compete with native species for food or habitat, alter the natural habitat, prey upon native species, and act as vectors for new diseases or parasites that could spread to native species. Any of these effects could have further widespread, detrimental impacts on native aquatic species and communities.

Aquatic invasive species arrived in North America through shipping (primarily in the Great Lakes region through discharge of ballast water), recreational boating, aquarium and water garden trade, release of live bait, live food fish trade, aquaculture, and man-made canals.  Once here, it is difficult to control or eradicate these species.  They will spread by hitching a ride on a trailered watercraft, and gear, and in bait buckets.  Examples of non-native aquatic species which have already invaded parts of Manitoba’s waters include: Rusty crayfish, Common carp, Rainbow smelt, and Asian tapeworm.etc.  Species of concern in proximity to Manitoba include Zebra mussel, Curly leaf pondweed, Round goby, and Spiny waterflea.

To protect our waters and to prevent further spread of aquatic invasive species in Manitoba take the following precautions:
CLEAN and inspect watercraft, trailer and gear. Remove all plants, animals and mud. Rinse using high pressure, hot tap water [50°C (120°F)}.
DRAIN all water from watercraft including the motor, livewell, bilge and bait buckets.
DRY watercraft for at least 5 days in the hot sun (if rinsing is not available).
DISPOSE of unwanted live bait and worms in the trash, and dump bait bucket water on land. Never release aquarium pets, plants or water into our lakes, rivers or wetlands.

Report sightings of aquatic invasive species calling the Aquatic Invasive Species Hotline (Toll Free in Manitoba): 1 87-STOP AIS–0 or 1 (877) 867-2470

For more information, visit: http://www.manitoba/StopAIS

The Invasive Species Council of Manitoba, a non-profit organization formed in 2006, is committed to promoting education and awareness and preventing the spread of aquatic invasive species in Manitoba.  For more information on invasive plants and animals, or to sign up for our free quarterly newsletter “Unwanted Invaders”, contact the Invasive Species Council of Manitoba at (204) 232-6021, This e-mail address is being protected from spambots. You need JavaScript enabled to view it or visit our website www.invasivespeciesmanitoba.com.