The Yellow Iris is a non-native plant in the United States, and is spreading throughout the country. It can be found growing abundantly in gardens all over the world thanks to its ability to colonize into large numbers that form a very dense stand which chokes out competing native plants.
The Yellow Iris was brought to the United States as an ornamental plant throughout the last century. Since its infestation into Wisconsin, it is now regulated and classified as a restricted plant. However, despite the regulations that are meant to control it, it is still sold online, bypassing state control efforts.
This invasive grows three to six feet tall and blooms bright yellow flowers from May to July each year. Like Garden Yellow Loosestrife, Yellow Iris spreads by seeds and underground rhizomes that lead to thick mats where several hundred plants may be present. Since the entire plant is poisonous, existing edible plants are destroyed, which in turn destroys the ecosystem for many wildlife species.
ERCLA volunteers began surveying Yellow Iris infestations in 2014 and found it to be present throughout the Chain, with the highest concentration found on Cranberry Lake. In 2015, ERCLA began a five year program of cutting this plant, which is the recommended method of control by the Wisconsin Department of Natural Resources.
ERCLA volunteers continue their monitoring efforts, including GPS waypoint locations that are included on a map produced by the Vilas County Mapping Department showing where Yellow Iris is present on the Chain. View more information on our information sheet as well as from the Wisconsin Department of Natural Resources.