What is an invasive plant?
An invasive plant is one that is not native to a particular ecosystem, whose introduction does or is likely to cause economic or environmental harm or harm to human health. It is capable of moving aggressively into an area, monopolizing light, nutrients, water, and space to the detriment of native species.
Why should you care?
Many familiar plants in our gardens and fields, and along roadsides are not native to New Hampshire. While the majority cause no harm to natural habitat or managed farms and forests, some do and are considered invasive plants. Invasive plants can reduce biodiversity, imperil rare species, reduce wildlife habitat by eliminating native foods or changing cover or nest sites, degrade water quality, reduce forest and farm crop production, and cause human health problems.
What is prohibited?
The State of New Hampshire has 27 plant species on a prohibited list. Some of these are already widespread, such as burning bush, buckthorns, multiflora rose, bittersweet, and Japanese barberry. For all the plants on this list the rule states: No person shall collect, transport, import, export, move, buy, sell, distribute, propagate or transplant any living and viable portion of any plant species, which includes all of their cultivars and varieties. New Hampshire lists another 24 plant species as restricted. These plants are not yet prohibited, but are exhibiting many of the invasive plant characteristics. Some of these are also familiar in our landscape including black locust and reed canary grass. The NH Invasive Plant Species Watch List is a non-regulatory reference identifying potentially invasive non-native plants,
The NH Department of Agriculture, Markets & Food regulates the plant industry including invasive species.
What can you do?
Learn to identify invasive plants
- Invasive Plant ID
- Prohibited Plant Species Poster
- Guide to New Hampshire Invasive Upland Plants
- Outsmart (UMass) Invasive Plants and Insects Videos
- Invasive Plants Field and Reference Guide: An Ecological Perspective of Plant Invaders of Forests and Woodlands
- NRCS Plant Database
Map and report
- Early Detection and Distribution Mapping System (EDDMaps)
EDDMapS is a web-based mapping system for documenting invasive species distribution. It combines data from many databases and organizations to create a national network of invasive species distribution data.
- Outsmart Invasives
EDDMapS has corresponding mobile phone apps for different regions of the country. In New England we use IPANE or Outsmart. By using this app you can report invasives on a smart phone or tablet while in the field and upload to EDDMaps. You can always edit your reports on a desktop back in the office or at home by logging in to your EDDMapS account
- Invasive Plant Atlas of New England (IPANE)
A comprehensive web-accessible database of invasive and potentially invasive plants in New England continually updated by a network of professionals and trained volunteers.
Take action in your community
- Join a volunteer workday
- Borrow tools from the seacoast tool lending library for community groups
- Look for hotspots in your community
- Invasive Plants in the Granite State: A Guide for Communities and Volunteer
- Picking our Battles: Enhancing Success of Invasive Plant Control Projects or as a pdf
Manage and control invasives
- Managing Invasive Plants: Methods of Control
- Control of Invasive Plants
- Best Management Practices for Roadside Invasive Plants (NH DOT)
- Best Management Practices for Mowing (NH DOT)
- Best Management Practices for Knotweed (NH DOT)
- Control Methods for Japanese Knotweed
- Mechanical Controls of Glossy Buckthorns
- Invasive Plants from Good Forestry in the Granite State pdf or html
Properly dispose of invasive plants
- Methods for Disposing Non-Native Invasive Plants
- Guidelines for Disposal of Terrestrial Invasive Plants
Use native plants for landscaping and conservation projects
- Alternatives to Invasive Landscape Plants
- NH State Forest Nursery (to purchase native seedlings)
- New England Wildflower Society (to purchase native plants)
- Landscape Trees and Their Susceptibility to Invasive Insects (fact sheet or poster)