Purple Loosestrife

Purple Loosestrife

Purple Loosestrife

Purple loosestrife was originally sold as an ornamental plant in Nebraska, but after its escape into the state's rivers, wetlands and marshes it was designated a noxious weed in Nebraska in 2001. Despite the sale of "sterile" cultivars in the nursery industry, and even those most owners of ornamental plants never saw any spread or escape in their own landscapes, sterile plants were producing viable seed after pollination by wild loosestrife plants.

Purple loosestrife is extremely difficult to control and once it gets into wetlands and rivers it has the ability to spread very rapidly. It is a perennial forb that originated in Eurasia and North Africa. It typically flowers from July to September, but this year with the warmer weather it is flowering in June and will continue to produce rose-purple flowers for the next few months. Its ability to produce flowers for extended time along its spike beginning at the bottom and slowly flowering to the top is one of the reasons it was a popular plant with homeowners, unfortunately it is also one of the reasons it is able to spread so rapidly on the rivers and in wetlands. Purple loosestrife is capable of producing millions of seeds that may lay dormant in the soil for many years. Another unique identification characteristic of the plant is its square 4-angled stem. 

Lancaster County Weed Control inspectors continue to find ornamental plantings occasionally, but they are very few compared to when it was first designated a noxious weed. We also have about 15 locations where purple loosestrife has spread into the wild. Those locations are being managed by the property owners. Chemical control has proven to be the most effective method to eradicate large infestations. Individual plants can be hand dug, completely removing all the root system, and put in a closed container to allow the entire plant to completely dry out before placing it in a tightly wrapped dark plastic bag to prevent contamination at the landfill.

Contact Information

We need everyone’s help, so if you would like more information on purple loosestrife or would like to report an infestation contact the Lancaster County Weed Control Office. Email: weeds@lancaster.ne.gov or phone (402) 441-7817. 

Purple Loosestrife

By Brent Meyer, Lancaster County Weed Superintendent