Ask Mr. Smarty Plants

Hyoscyamus niger, Black henbane is Meditteranean in origin, and most of the information we found had to do with its supposed medicinal properties, as in this Henriette's Herbal Homepage Hyoscyamus. Particularly since you are working with young people, you need to read all of this to pick up on the various cautions that abound in connection with it. Also read this article from Wikipedia, Hyoscyamus niger, Black Henbane. It will scare the daylights out of you, just knowing what family of plants it belongs to, and all the damage it can do. Since this plant is Eurasian in origin, there is no information on it in our Native Plant Database, but we think it is important enough to try to find some deterrents.

This Idaho's Noxious Weeds site Black Henbane has several links to possible treatments for it. From invasive.org there are a number of illustrations and some more links -black henbane. The Utah State University Cooperative Extension Range Plants of Utah - Black Henbane has some suggestions for management, including the specific names or components of herbicides that are effective on it.

Since Glacier County is on the northwest corner of Montana, on the border with Canada, it has a USDA Hardiness Zone of 4a to 4b, so obviously this plant can survive very cold temperatures.  We recommend you contact the Montana State University Cooperative Extension Office for Glacier County. Hopefully, they will have information on getting rid of this plant.

Black henbane is an annual or a biennial, and blooming should be beginning now, so the very first thing to do is preventing it from seeding, by pulling it out or at least cutting off the buds or blossoms from every plant anywhere around. The dead stalks should be pulled out, although we don't know how extensive the root sytem is. Any plant that you can pull out whole, roots and all, is a gold star. Dispose of all remnants so that no seeds can get back into the soil. Take the advice of the university experts on whether to even use that soil that you have built into raised beds. The plant adores rich, moist soils, so you invited it, although you didn't mean to. 

More pictures of Black Henbane from Google.