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Weed Control

Black Henbane: A Noxious Poisonous Weed

By June 23, 2023June 26th, 2023No Comments
Black henbane

Black henbane has been in the news in Calgary recently, and not for good reasons.

Black henbane (Hyoscyamus niger) is a poisonous plant and is classified as a noxious weed under the Alberta Weed Control act. With noxious weeds, according to the act, the goal is to prevent it from spreading.

Black henbane typically grows as a weed in disturbed areas, roadsides, and agricultural fields. While it can be found in various locations, including lawns, its prevalence in residential lawns in Calgary specifically may vary and is not considered a common weed to find.

Photos – Our team has been hired to spot spray for black henbane along Calgary roadways

Black henbane is not only unsightly but poses a concern for homeowners due to its toxicity and potential harm to humans and animals if ingested. Contact with human skin can also cause a rash.

If you do have black henbane on your property, it can be a problem for homeowners in Calgary, as it is an invasive weed that can quickly spread and compete with native vegetation. It is important to be cautious and take appropriate measures to prevent its growth and eradicate it if it appears in your lawn.

According to CBC News, it has become more visible in Calgary in 2023, partially due to the weather.

To prevent and get rid of black henbane in your lawn or garden, consider the following steps:


Learn to identify black henbane by its distinctive features, including green-gray leaves, purple-brown flowers, and a foul odor.

Manual removal

Wear gloves and protective clothing, and manually pull out black henbane plants from the root, ensuring that you remove the entire plant to prevent regrowth. Throw in your black cart; to prevent it’s spread, do not compost by putting in your green bin.


Apply a thick layer of organic mulch, such as wood chips or straw, around desirable plants to suppress weed growth and make it difficult for black henbane to establish itself.


If manual removal is not sufficient, consider using herbicides specifically labeled for controlling broadleaf weeds like black henbane. However, exercise caution and follow the instructions carefully to avoid harming desirable plants and the environment. Consult with a local garden center or lawn care professional for advice on suitable herbicides. If you have problems with Black Henbane, and don’t have the time or energy to deal with on your own, we can help. Learn more about our residential vegetation control services here and commercial vegetation control services here.

Regular maintenance

Maintain a healthy and dense lawn or garden by proper watering, mowing, and fertilizing. A well-maintained landscape helps prevent the establishment of invasive weeds like black henbane.

Early detection and prompt action

Regularly inspect your lawn and garden for signs of black henbane or any other weeds. If you spot any, take immediate action to prevent their spread.

If you see black henbane on municipally-owned property in the City of Calgary, call 311 and report it.

At Earth Smart Property Solutions we have been dealing with weed control since 1989. If you have any questions on lawn care and weeds, then please be sure to to contact our team of lawn care professionals in Calgary or Red Deer and they will be able to help.


CBC News, Beware the black henbane, a toxic plant that’s appearing in Calgary