Observation: This is a very annoying invasive plant. It started growing from where old birdseed was dumped. It now occupies about 30% of of our yard. We cannot seem to eradicate it. We have no idea what type of plant it is. How worried should we be and how does this happen – by eating? - touching? or ???
Cooperative Extension Service (CES) Consult: Gino Graziano, Invasive Plant Instructor writes, "Yes, unfortunately that is split lip hempnettle, and it will grow wherever there is open space. Regularly and thoroughly pulling or cutting hempnettle will diminish the population, but won't fully get rid of it. Planting something aggressive like grasses, combined with regular cutting will help too. Weed barrier fabrics can also help. There are herbicides that can work especially when combined with planting, but talk to me first because the affected area plays a role in what products you should use. Keep an eye out for this plant in your community because it may have spread further, but can be contained. Feel free to follow up with me on documenting, or getting rid of this plant." University of Alaska Fairbanks (2016-08-10)
CES Consult: Gino Graziano continues, "Hempnettle spreads around the state prolifically on items like soil, gravel, and sometimes animal feeds. You won't get sick touching it. I am not sure how it affects you if eaten, but I wouldn't eat it. I would suggest controlling it. It pulls easily, but you will have to pull it regularly. This will work though if it is a new infestation, and you keep at it. You may also try covering the area with a tarp, cardboard or other item that will prevent it from growing. I don't know how long you will have to leave it there. There are herbicides that will work on it as well, I can consult on that too if desired." University of Alaska Fairbanks (2016-10-28)
Resource:
Cooperative Extension Service, University of Alaska Fairbanks
Invasive Plants is defined as a species that is, (1) non-native to the ecosystem under consideration and (2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health. (Executive Order 13112) .
Non-Native Plant Species of Alaska (.PDF last updated 2006, 29 November):
- Splitlip hempnettle (Galeopsis bifida Boenn.)
- Brittlestem hempnettle (Galeopsis tetrahit L.)
