Leafy Spurge

Leafy Spurge

Euphorbia esula
Leafy-Spurge-Chris-Evans-University-of-Illinois-Bugwood.org-1
Leafy Spurge (Photo by Chris Evans, University of Illinois, via Bugwood.org)

Status in Squamish:

PREVENTION-WATCHLIST

Status in Whistler:

PREVENTION-WATCHLIST

Status in Pemberton:

PREVENTION-WATCHLIST
Vectors of Spread:
Synonyms

Also known as “Wolf’s Milk”

ID Characteristics

Flowers: The small umbrella-shaped flowers are yellowish-green and lack petals and sepals. The flowers are supported by two heart-shaped, green, leaf-like bracts.

Stem: Mature plants range from 0.2-1.0 m and contain a milky, white sap. The stems are smooth and hairless.

Leaves: The narrow, waxy leaves are attached directly to the stem and are up to 7 cm long. The leaves are blue-green in the spring and early summer and turn reddish-orange in late summer.

Fruit: The light grey or dark brown seeds are 2 mm long, smooth, and oblong. The seeds grow in pods that explode when dried.

Roots: The brown, woody roots penetrate deep into the ground (up to 5 m) and form an extensive lateral root system that can spread over 8 m.

Similar Species

Invasive:

Cypress Spurge (C.O’Brien)

Cypress Spurge  (Euphorbia cyparissias) is a similar looking plant, and is also invasive in the Sea to Sky region. Cypress Spurge grows its branches more compactly than the Leafy Spurge, and has shorter, narrower leaves.

 

 

 

 

Report

Please report any sighting of Leafy Spurge by clicking here.

Habitat and Origin

Native to central and southern Europe, Leafy Spurge was introduced to eastern North America in the early 1800s. It was originally introduced as either an ornamental or as a contaminant in crop seed. It was first recorded in Canada in 1933.

Leafy Spurge is a versatile plant that can inhabit a wide range of conditions, from rich damp soils to nutrient-poor, dry, sandy, or gravelly soils. Often seen in croplands, pastures, rangelands, woodlands, and roadsides.

Current Distribution

Propagation & Vectors of Spread

Leafy Spurge can reproduce through both seeds and vegetative methods. One large plant can produce up to 130, 000 seeds that stay viable in the soil for 5 to 8 years. When reproducing via vegetative methods, new buds are formed from the spreading roots. One plant can form up to 300 new buds from a single root mass.

Leafy Spurge can locally spread by vegetative reproduction through the root systems, but long-distance dispersal occurs through the transport of seeds. The seed pods dry in the late summer and fall and explode, shooting seeds up to 5 m from the parent plant. They are then transported further by water, animals, and human activity.

Ecological, Economic, & Health Impacts

Ecological: 

  • Reduces native grassland biodiversity.
  • Decreases forage for wildlife.
  • Increases soil erosion.

Economic:

  • Reduces property values.
  • Irritates feet, mouth, and stomachs of livestock.

Health:

  • Causes skin irritation in humans.
What Can I Do?

Leafy Spurge is NOT currently found throughout the Sea to Sky Corridor, so the best approach to controlling its spread is by PREVENTION.

 

Learn to identify Leafy Spurge: use the images presented in this profile page to learn how to identify Leafy Spurge

What to do if you spot it: You can report any Leafy Spurge sighting by clicking here.

 

DO:

  • Regularly monitor properties for weed infestations.
  • Ensure soil and gravel are uncontaminated before transport.
  • Check wildflower mixes to ensure that they do not contain Leafy Spurge.
  • Minimize soil disturbances (e.g., use grazing plants that prevent soil exposure from overgrazing), and use seed mixes with dense, early colonization (e.g., alfalfa or barley) to revegetate exposed soil and resist invasion.
  • Ensure that plants are disposed of in a garbage bag if found in floral arrangements to prevent seeds from spreading.

 

DO NOT:

  • Do not unload, park or store equipment or vehicles in infested areas; remove plant material from any equipment, vehicles or clothing used in such areas and wash equipment and vehicles at designated cleaning sites before leaving infested areas.
  • Do not plant Leafy Spurge in a garden, no matter how well-contained its enclosure may seem.
  • Do not move soil that has been contaminated with Leafy Spurge.
  • Do NOT compost!

 

Control

Mechanical

  • Mow/till regularly to reduce weed progression; plant material can be left on site to decompose.
  • If in the post-flowering stage, all plant parts must be bagged and deeply buried at landfill.
  • When tilling, be sure to prevent machinery from spreading root fragments to new sites.
  • Intense cultivation should be done in spring, 2 – 4 weeks before the plant emerges, tilling at least 7 cm deep, and continue every three weeks until the soil freezes.

Chemical

  • Herbicide use is highly time dependent. When the plant is in the true flowering and seed production stage (from mid-June), it is most susceptible to a combination of dicamba and 2,4-D, a combination of picloram and 2,4-D or picloram alone.
  • However, picloram is not suitable for wet, coastal soils.
  • Glyphosate also provides good Leafy Spurge control when applied during the active growth phase.
  • We recommend that any herbicide application is carried out by a person holding a valid BC Pesticide Applicator Certificate. Before selecting and applying herbicides, you must review and follow herbicide labels and application rates; municipal, regional, provincial and federal laws and regulations; species-specific treatment recommendations, and site-specific goals and objectives.

Biological

  • Some biological agents exist, including root feeding beetles (Aphtona cyparessiae, Aphtona czwalinae, Aphtona flaca, Aphtona nigriscutis), and foliar feeding moths (Hyles euphorbiae).

Cultural

Sheep and goats will readily graze on young Leafy Spurge plants, which can lower seed production and decrease the spread of the plant.

References

Alberta Invasive Species Council, Leafy Spurge, https://abinvasives.ca/wp-content/uploads/2017/11/FS-LeafySpurge.pdf

City of Edmonton, Leafy Spurge, https://www.edmonton.ca/programs_services/pests/leafy-spurge.aspx

Government of Canada, Managing leafy spurge with a hungry beetle, https://www.agr.gc.ca/eng/agriculture-and-climate/agricultural-practices/agricultural-pest-management/agricultural-pest-management-resources/managing-leafy-spurge-with-a-hungry-beetle/?id=1544800508868

Government of Saskatchewan, Leafy Spurge, https://www.saskatchewan.ca/business/agriculture-natural-resources-and-industry/agribusiness-farmers-and-ranchers/livestock/pastures-grazing-hay-silage/problem-weeds—a-cattlemens-guide/leafy-spurge

Invasive Species Council of BC, Leafy Spurge, https://bcinvasives.ca/invasive-species/identify/invasive-plants/leafy-spurge

Invasive Species Council of Manitoba, Leafy Spurge, https://invasivespeciesmanitoba.com/site/index.php?page=leafy-spurge

Nature Conservancy of Canada, Leafy Spurge, https://www.natureconservancy.ca/en/what-we-do/resource-centre/invasive-species/leafy-spurge.html

Ontario Ministry of Agriculture, Food, and Rural Affairs, Leafy Spurge, http://www.omafra.gov.on.ca/english/crops/facts/info_spurgeleafy.htm

Province of Manitoba, Leafy Spurge, https://www.gov.mb.ca/agriculture/crops/weeds/leafy-spurge.html

Saskatchewan Invasive Species Council, Leafy Spurge, http://www.saskinvasives.ca/ckfinder/userfiles/files/Leafy%20Spurge.pdf

University of California, Weed Control in Natural Areas in the Western United States, https://wric.ucdavis.edu/information/natural%20areas/wr_E/Euphorbia_esula-oblongata-terracina.pdf