Close Alert Banner
Learn More
Skip to Content
A-Z ServicesAccessibilityCareersReport a ConcernContact Us
View our Facebook Page View our Twitter Page View our YouTube Page View our LinkedIn Page

County of Haliburton Logo County of Haliburton Logo

Contact Us
  • Living Here
    • Animal Services
    • Cemeteries
    • Community and Social Services
    • Community Map
    • Consultations
    • Emergency and Health Services
    • Event Calendar
    • Explore the Haliburton Highlands
    • Garbage and Recycling
    • Library
    • Property and Environment
    • Property Taxes
    • Recreation
    • Who Does What
    View our Emergency Preparation page
    Emergency Preparation
  • Roads and Trails
    • Addressing
    • Adopt-A-Road Program
    • Bids and Tenders
    • Capital Projects
    • County Road 21 Corridor Study
    • Report a Concern
    • Road Maintenance
    • Roads and Sign Permits
    • Trails
    Open new window to view our Interactive Road Closure Map
    Road Closure Map
  • Planning and Maps
    • Bids and Tenders
    • Bylaws
    • Climate Change
    • Consultations
    • Maps
    • Planning Services
    • Property and Environment
    • Shoreline Preservation
    Open our interactive GIS mapping in a new window
    County GIS Maps
  • County Office
    • Accessibility
    • Applications, Licences and Permits
    • A-Z Services
    • Bids and Tenders
    • Bylaws
    • Careers
    • Commissioner of Oaths
    • Contact Us
    • Finance and Budget
    • Freedom of Information
    • News and Notices
    • Report a Concern
    View our Finance and Budget page
    Finance and Budget
  • Council
    • Accountability and Transparency
    • Agendas and Minutes
    • Bylaws
    • Committees
    • Council Meetings
    • Meet Your Council
    • Speaking Before Council
    View our Meet Your Council page
    Meet Your Council

woman kayaking in a lake

Noxious Weeds

HomeLiving HereProperty and EnvironmentNoxious Weeds
  • Open new window to share this page via Facebook Facebook
  • Open new window to share this page via Twitter Twitter
  • Open new window to share this page via Pinterest Pinterest
  • Open new window to share this page via LinkedIn LinkedIn
  • Email this page Email

The County of Haliburton has a Forest Conservation Bylaw Officer who is available to speak to groups and the public about forestry, the County's bylaws, and invasive species and weeds.

Below, you will find information on three of the more common invasive species found in Haliburton County.

Garlic Mustard

Garlic mustard is an invasive herb native to Europe. Since its arrival in North America it has escaped into the wild and is now one of Ontario's most aggressive forest invaders. The Garlic Mustard plant has a distinctive onion-like or garlic-like odour and flowers from May to June.

Stems & Roots

Stems up to 1m (40 in.) tall, simple or little branched, smooth or with a few simple hairs.

Leaves

Leaves differ from year 1 to year 2. Year 1: the leaves in rosette form (circular cluster of leaves growing from the base of the stem) 3-4 leaves per rosette, dark green and kidney shaped with scalloped margins and deep veins which make them look wrinkly. First year leaves emit a strong garlic smell when crushed. The 2nd year leaves grow alternately along the stem of the plant. They are more triangular in shape and have coarse teeth. Lower stem leaves are larger growing up to 10 cm (4 in.) wide and kidney-shaped. Upper leaves are more triangular and smaller growing from 5 – 10 cm wide and narrowing at the tip.

Flowers

Flowers only occur in the 2nd year plants, and are small and white with 4 petals (3-6 mm long and wide. Seedpods (called siliques)may be in the axils of small leaves; 2.5-6cm long, spreading, and borne on short pedicels about as thick as the pods; their beaks slender, 1-3mm (1/25-1/8 in.) long; seeds black, 3mm (1/8 in.).

Garlic mustard diagram

Learn more

Below are links to more information about the Garlic Mustard plant:

  • http://www.omafra.gov.on.ca/english/crops/facts/ontweeds/garlic_mustard.htm
  • http://www.ontarioinvasiveplants.ca/files/unwantedlettersGarlicMustardFINAL.pdf
  • https://www.ontarioinvasiveplants.ca/wp-content/uploads/2016/07/OIPC_BMP_GarlicMustard.pdf

Dog Strangling Vine

Dog-strangling vine is an invasive perennial herbaceous plant in the milkweed family (Asclepiadaceae). It is spreading rapidly and causing damage to ecosystems in certain areas throughout Ontario.

Stems & Roots

Stems are vine-like, with fine hairs and are herbaceous or have a woody base that can twine or climb on available structures within its reach. Stems will also twine around themselves forming dense mats of vegetation. Plant overwinters successfully in Ontario, and grow 1-2m (3-6.5 ft) long.

Leaves

Opposite (2 per node), smooth green with entire to wavy margins, oval to oblong with rounded bases and abruptly pointed tips. Leaves can range in size from 7-12 cm (3-5in) long and 5-7 cm (2-3in) wide. Leaves are rounder and smaller near the base of the plant, largest at the mid-section and smaller and narrower towards the top

Flowers & Fruit

Small flowers purple-brown or dark purple to pinkish in colour, in small umbel-like clusters (5-20 flowers per cluster) at tips of stems and upper branches; seedpods slender, 4-6cm (1.5-2.25 in) long, broadest near the base and long-tapered to a slender tip, opening along one side and releasing many, small, flat, brownish seeds with long, white, feathery tufts of hair (called coma). All parts of the plants may contain small quantities of white, milky juice. Flowers from late June until autumn.

Diagram of dog vine

Learn more

Below are links to more information about Dog Strangling Vine:

  • http://www.omafra.gov.on.ca/english/crops/facts/ontweeds/dogstrangling_vine.htm
  • OMNRF Fact Sheet
  • http://www.ontarioinvasiveplants.ca/files/unwantedlettersDSVFINAL2.pdf
  • https://www.ontarioinvasiveplants.ca/wp-content/uploads/2016/07/OIPC_BMP_GarlicMustard.pdf

Giant Hogweed

Giant Hogweed (Heracleum mantegazzianum) is a perennial plant and a member of the carrot family. It is a garden ornamental from southwest Asia that is naturalizing in North America and becoming more common in southern and central Ontario. Giant hogweed has the potential to spread readily and grows along roadsides, ditches and streams. It invades old fields and native habitats such as open woodlands.

Stems & Roots

Typically 10-15cm (4-6in) in diameter with coarse hairs, flowering stems up to 5m (16ft) high, hollow except at the nodes; both stems and petioles having conspicuous reddish-purple flecks throughout and sometimes completely purple near the base; lower stem often very rough with sharp-pointed, irregularly-spaced bumps.

Leaves

Leaf blades of rosette leaves very large, up to 1m (40in.) across. Compound leaves with 3 large deeply cut leaflets, each leaflet with deep irregular lobes and coarse, sharp teeth on all margins; their petioles (stalk that joins the leaf to the stem) often have sharp-pointed bumps similar to those on the flowering stems; leaves on the flowering stem are of similar shape but smaller, the upper ones often not divided but just deeply 3-lobed.

Flowers & Fruit

White or rarely pinkish in colour, appear in mid-june and are clustered in an umbel shaped head and can measure up to 120cm (4ft) across. Umbels are an umbrella shaped cluster of short-stalked flowers, typical of the carrot family. Each compound umbel consist of many (approximately 30 to 50) branches, each branch ending in a simple umbel with approximately 30 to 40 flowers

Caution

It has been implicated as a cause of severe dermatitis in a few susceptible individuals.

Giant Hog Weed

Learn more

More information on the Giant Hogweed can be found at the links below:

  • Hogweed lookalikes
  • Giant Hogweed (Fact Sheet)
  • OMNRFs factsheet
  • Omafra's Giant Hogweed Information Page
Living Here
    • Animal Services
    • Cemeteries
    • Community and Social Services
    • Community Map
    • Consultations
    • Emergency and Health Services
      Toggle Section Emergency and Health Services Menu
      • Emergency Preparation
      • Paramedic Services
        Toggle Section Paramedic Services Menu
        • Ambulance Call Reports
        • Feedback and Quality Assurance
        • Privacy Statement
        • Public Access Defibrillation
    • Event Calendar
    • Explore the Haliburton Highlands
    • Garbage and Recycling
    • Library
    • Property and Environment
      Toggle Section Property and Environment Menu
      • Addressing
      • Building Permits
      • Climate Change Planning
      • Flood Preparation
      • Forestry
      • Internet
      • Noxious Weeds
      • Shoreline Preservation
      • Source Water Protection
    • Property Taxes
    • Recreation
    • Who Does What

Contact Us

Subscribe to this page

County of Haliburton - Footer Logo

County of Haliburton Administration Office
11 Newcastle St., PO Box 399, Minden ON K0M 2K0

© 2020 The County of Haliburton

Designed by eSolutionsGroup

About

  • Living Here
  • Roads and Trails
  • Planning and Maps
  • County Office
  • Council

Resources

  • Accessibility
  • Freedom of Information
  • Terms of Use
  • Sitemap
  • Website Feedback

Contact

Phone: 705-286-1333
Fax: 705-286-4829
Email Us
Contact Us

View our Facebook Page View our Twitter Page View our YouTube Page View our LinkedIn Page
Close Old Browser Notification
Browser Compatibility Notification
It appears you are trying to access this site using an outdated browser. As a result, parts of the site may not function properly for you. We recommend updating your browser to its most recent version at your earliest convenience.