Field Guide     Weed Management     Leafy Spurge

Leafy Spurge (Euphorbia esula L.)

Crop Impacts: Pastures

Leafy Spurge 1

About Leafy Spurge:

Leafy Spurge is a perennial weed that reproduces by its seeds along with their large root system which has a lot of small pinkish buds that form new shoots. This plant is not typically ingested by livestock, but large amounts can infect hay and poison livestock.

Family: Spurge Family (Euphorbiaceae)

Leafy Spurge 2

Leafy Spurge Scouting and Prevention:

The Leafy Spurge has a straight stem that stands up to 1m tall, with many leaves 3 to 7cm long, wedge or linear in shape, alternating 1 per node and sometimes in clusters or sitting opposite of each other. This weed produces greenish inflorescences that consist of 7 or more branches, which form an umbel-like cluster at the top of the main stem. The tiny, unisexual flowers have several pollen producers which are male flowers consisting of only one tiny stamens without petals or sepals. The seed producing flowers, or in other words the female flowers, have one pistil and once again do not have petals or sepals, sitting in a crowded cup-like structure. The rim of this structure has 4 tinny lobes and 4 yellowish U-shaped glands. Inside this structure there are one female, and many tiny male flowers which are called a cythium. The seedpods of the Leafy Spurge are 3-lobed, grayish to yellowish or brownish, smooth with a small bump at the base, containing 3 seeds. This seedpod will explode when it is dry throwing the seed for quite a few meters. In the spring, Leafy Spurge is deep green to almost bluish-green. June and July is the flowering period of Leafy Spurge, during this time the plant changes colours to a yellowish-green or olive-green, and occasionally has another flowering period in late August or September. After flowering, the plant will change back to a dull green or even a reddish-green.

Common locations

  • - Cultivated lands
  • - Pastures
  • - Gardens

Prevention

Prevention of Leafy Spurge is less expensive and less time-consuming than trying to control it. Contaminated hay is the main source for the spreading of Spurge weeds. Make sure when you are seeding a new area you are doing so with certified weed-free seeds. It is also very important that you prevent overgrazing by livestock to help desirable grass stay strong and dense. If there is an infested area on your property, be sure to drive around, instead of through it. Finally, make sure to give all equipment that has been in infested fields a good clean, to make sure no seeds are transferred.

Leafy Spurge Control:

It is recommended to use a combination of both chemical and cultural control methods to take control of Leafy Spurge in your row crop fields. Due to its very difficult nature to control, this combined process should be repeated for 4 to 5 years.

Cultural Control

If you are looking for cultural control methods, mowing rapidity every 21 days can be an adequate method. Your first mow should be done between May to July, or when the first bloom is. It is important to note that mowing may stimulate the development of new buds. Making sure you have a good crop rotation is extremely important in keeping Leafy Spurge under control. Having wild rye, wheatgrass or brome in your rotation creates significant top growth, becoming especially effective against Leafy Spurge growth. If you plant winter crops like fall rye it provides crop competition in the fall after herbicide treatment or tillage has been done, and repeated again in spring. Finally, repeated tillage in combination with herbicide application works well. During growing season it is best to cultivate infested areas every 3 weeks. If the infested fields have crops in them, two post-harvest cultivations every year for 3 to 4 years has shown to be an effective measure of control. This repetitive cultivation may be bad for areas where soil erosion is a concern or in minimum tillage programs. The occurrence of tillage will be reduced with fall herbicide application. For the best control over Leafy Spurge, spray herbicides a minimum of one week before tillage to allow the chemicals to enter the root system of the weed.

Chemical Control

One single application of herbicide treatment will not completely eradicate Leafy Spurge. Annual treatment should be done until you have a minimum of 90% control over leafy spray or it will re-establish. That being said when applying herbicides to Leafy Spurge it is best done when the plant is in early bud which may be in late spring, early summer or late summer. Amitrol-T herbicide has been shown to give season-long control, but application will need to be reapplied the next year. Bamvel gives reasonable top growth control and will last the majority of the growing season under favorable weather conditions. Finally, applying 2,4-D amine will only give temporary control of the top growth of Leafy Spurge. This herbicide treatment will require at least one additional application in the same growing season.

Latin / Alternative Leafy Spurge names:

  • - Euphorbia esula L.
  • - Euphorbe ├ęsule
  • - Euphorbe feuillue

Additional Leafy Spurge Resources

http://www.omafra.gov.on.ca/english/crops/facts/ontweeds/leafy_spurge.htm

http://www.omafra.gov.on.ca/english/crops/facts/info_spurgeleafy.htm

http://www.gov.mb.ca/agriculture/crops/weeds/print,integrated-management-of-leafy-spurge.html#chemical