Yellow Flag Iris
City of Burnsville staff recently observed several populations of an invasive plant – Yellow Flag Iris – on the shoreline of Crystal lake within Crystal Lake West Park. While many invasive species (such as buckthorn) are common and well-known, Yellow Flag Iris may be lesser known to Burnsville residents.
This plant is of concern because it grows into dense patches that can take over an entire shoreline, narrow waterways and out-compete native vegetation. It can even be spread between water bodies by pieces of roots and by seed. It is very difficult to eradicate once established in a waterbody, so now is a good time to be proactive while it is still relatively rare at Crystal Lake.
Residents are highly encouraged to remove any populations of Yellow Flag Iris growing on their property’s shoreline. This will help prevent it from taking over your shoreline, your neighbor’s, and the nearby parkland. Plants can be dug out, just make sure to get all the roots since it can re-grow from fragments. Wear gloves as the plant can be a mild skin irritant.
Please note that there is a very similar native species called Blue Flag Iris. When flowers are not present, it is very hard to tell the two iris species apart so I would not recommend attempting to control Yellow Iris unless you are able to confirm the identification with the flowers.
A permit is required to manage plants that are within or immediately adjacent to public waters but the process of obtaining a permit is quite simple. Just visit the MN Permitting & Reporting System website to get started: https://www.dnr.state.mn.us/mpars.
Thank you for your help in protecting Crystal Lake.
Natural Resources Specialist
City of Burnsville