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 and the Maine Natural Areas Program (MNAP) are collaborating with the US Fish and Wildlife Service (USFWS) on a new project to map Pepperweed in Maine and New Hampshire and work towards eradication.

From 2021 to 2022 the parternship will work collaboratively in Maine & New Hampshire to build a comprehensive map of existing populations, support ongoing eradication efforts and coordinate public engagement. If you have questions about Pepperweed in Maine, please visit the Maine Natural Areas Program webiste.  


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  

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 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.