War on Weeds: Poinsettia

North Carolina State University

www.plantsrescue.com

This weed may invade your land. Be ready to oppose it.

The Enemy: Poinsettia (Euphorbia pulcherrima)

Strategy: During the 14th to 16th centuries, poinsettia sap was used to control fevers. The bracts (modified leaves) were used to make a reddish dye. Joel Roberts Poinsett was the first U.S. ambassador to Mexico, being appointed by President John Quincy Adams in the 1820s. In 1828, he found a beautiful shrub with large red flowers growing next to a road. He took cuttings from the plant and brought them back to his greenhouse in South Carolina. Even though Poinsett had an outstanding career as a U.S. congressman and as an ambassador, he will always be remembered for introducing the poinsettia into the U.S.

Attack: Poinsettias normally do not become a weed, especially because they do not adapt to our regions, although many are grown in geothermal greenhouses near McCall. The milky sap, as with all euphorbias (leafy spurge), can be toxic and cause skin and eye irritations, especially in children. The plant has been known to be a weed in regions of Mexico where it grows as a shrub along roadsides and causes problems similar to brush species in the United States.

Defense: Most people here simply throw them away. Eighty percent of the Poinsettias purchased in the U.S. are purchased by women, mostly red poinsettias. If it does become a problem, simple mechanical control is available. If you have had them in your house for awhile, you will find a white fly that likes to attack them and other plants. Simple herbicides such as 2,4-D will take the plant out as long as you spray it early in the season. As with other weeds, you know — a plant out of place — proper identification is key to controlling it.


To learn more, call Bonneville County Weed Superintendent Jeffrey Pettingill at 208-529-1397 or email weeds@co.bonneville.id.us.


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