One found in NH, One not yet in NH

invasive plants tree of heaven and giant hogweed

The N.H. Department of Agriculture, Markets & Food is asking people to be on the lookout for two invasive plants. Click on the images for a larger view.

Tree of Heaven (Ailanthus altissima)

invasive plant tree of heaven Ailanthus altissima
Photo by Chuck Bargeron, University of Georgia,

Tree of Heaven is a fast-growing plant that has been found in New Hampshire. While the distribution map found on EDDMapS makes it look like a lost cause, it’s not as bad as it looks. We’re in the early stages of the invasion, and the Department of Agriculture, Markets & Food is hopeful that it can be eradicated. Look for it in cities and especially along railroad tracks, which is where it’s been found so far. At this time, thankfully, it hasn’t been found in our woodlots and natural areas. If you think you’ve found it, please send a picture to the UNH Cooperative Extension Education Center.

Giant hogweed (Heracleum mantegazzianum)

invasive plant giant hogweed Heracleum mantegazzianum
Photo by Jean-Pol GRANDMONT, Creative Commons

While you may have heard about giant hogweed in the news recently, there are currently no known locations of it in New Hampshire. About a decade ago, several sites were eradicated and close monitoring shows no return so far. Cow parsnip (Heracleum maximum) is a similar looking plant and it is native to New Hampshire. It is from the same family (Apiaceae) as giant hogweed. Both of these plants can cause harm to humans in the form of skin irritations, which may include severe blistering and burns (though, some researchers have said fewer people have problems with our native cow parsnip). So, if you think you see either giant hogweed or cow parsnip, don’t grab them with your bare hands! Again, if you think you see giant hogweed, send pictures to the UNH Cooperative Extension Education Center.

Read more about both of these and other plants in the New Hampshire Guide to Upland Invasive Species.