Driving through the area late this summer, you may have noticed an abundance of these beautiful purple flower spikes. You’ll see them in the low-lying fields, swamps, and ditches along the road. I snapped these photos on the side of Route 114 near the New London-Sutton town line.
Though beautiful, these herbaceous perennials are the highly invasive Lythrum salicaria. Purple Loosestrife, as it is commonly known, is native to Europe and Asia and spreads very easily in NH by seeds and cuttings. As colonies of this plant form, they choke out and displace species native to our sensitive wetland environments. Purple Loosestrife alters the plant communities living in wetland areas, reducing the natural habitat and food sources for the fauna in these areas.
Purple Loosestrife has no natural predators in this area, though biological controls including some beetles are being studied and considered to manage the invasive threat. The best approach to removal is physically pulling entire plants before they seed and burning the remains, though this is probably unfeasible for large colonies. Consider reaching out to the NHDES Exotic Species program for more information and best practices to deal with any invasive species you may come across.