Perennial Pepperweed Partnership


Pepperweed (Lepidium latifolium) is a relatively new invasive plant to Maine and New Hampshire, though it is well established just to our south in Massachusetts. It is a threat to our native plants, animals and landscape. UNH Extension collaborated with the US Fish and Wildlife Service (USFWS) to map Pepperweed in Maine and New Hampshire and work towards eradication in 2021 and 2022. Pepperweed is currently found in 10 sites in NH, which are actively managed by NH Department of Environmental Services. 

Click here to read the final report from the project. 



We need help building a comprehensive map of where Pepperweed is in Maine and New Hampshire.

1. Learn To Identify Pepperweed.

Pepperweed can be found in coastal salt marsh and upland roadsides. It grows 1-5 feet tall and flowers mid-june to mid-August in Maine and New Hampshire. Below is a card with several photos and helpful tips for identification:

Identification Card

Identification Video

2. If You See it, Report it.

Think you spotted Pepperweed? It's easily to report it, there are simple instructions below for Maine and New Hampshire:

Report a Sighting in Maine

Report a Sighting in New Hampshire



We hosted a webinar in early June of 2021 to explain this partnership, identify opportunities to learn about and collaborate on monitoring and eradication efforts. You can watch the recording of the zoom presentation here.


Extension State Specialist, Community Volunteers
Phone: (603) 862-2166
Office: Cooperative Extension, Nesmith Hall, Durham, NH 03824