Jimsonweed, also known as Devil’s Trumpet, is a tall, bushy annual herb that has been introduced most likely through contamination of agricultural seeds. If found, please contact the Rural Services Office at 780.681.3929 or toll free at 1.866.681.3929. Flowers typically appear between July and September.
Jimsonweed is federally classified as a Class 2 (Primary Noxious) weed under the Weed Seeds Order of the Canadian Seeds Act, therefore allowing small concentrations to be present in seed mixes. All parts of Jimsonweed are toxic to both humans and animals as the plant contains dangerous levels of the alkaloids classified as anticholinergics (block neurotransmitters) and has been used for its psychoactive effects (affecting mood and behaviour). It has been found in Canola fields while producers where swathing, in Barrhead, Leduc and Westlock counties.
Habitat and Identification:
Jimsonweed can be found in moist nutrient-rich soil, especially those with high nitrogen content. The stems are tall, hollow, extensively branched, red to purplish, hairless or with small hairs and can grow to be 0.5 to 2m tall. Mature leaves are alternate, simple and on petioles up to 12cm long. The leaves themselves are 5-25cm long and 4-25cm wide, ovate (egg-shaped), the tips pointed. The Leaves are hairless, unevenly toothed and smell foul when crushed.
Jimsonweed flowers are trumpet-shaped, 5-lobed, are white or purplish in color and foul-smelling. Flowers appear between July to September. The seed pod is an erect, oval-shaped capsule, and densely covered in spines fairly equal in size. When seed pods are ripe the seed capsule will explode and expel up to 600-700 seeds per capsule.
Ask for the seed analysis results, and refuse crop seed that carries Jimsonweed seeds as well as any other regulated weed seed. Make sure to wear protective clothing and dispose of bagged plant material in the landfill. Do not compost or burn as the toxins release in the air may cause secondary poisoning.
Do not graze as Jimsonweed is poisonous. Seedlings are readily killed by tillage operations. Older plants may regenerate from the lower nodes if clipped or trampled. Severed branches with viable seeds will continue to ripen. Hand-pulling is best done before seed production occurs. Herbicides with the active ingredients bentazon, metribuzin, acifluorfen, chlorthal and glyphosate are a few registered for use.