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A Golden Success: Yellow Flag Iris Removal at Big McGraw Lake

07/17/202607/20/2026

There are many duties that fall under the title of a Wild RIvers Conservancy Invasive Species Intern, one of them being yellow flag iris removal.

What is Yellow Flag Iris

Yellow flag iris is an invasive flower that competes with our native blue flag iris and easily spreads in areas near bodies of water. For more on how and why this plant spreads so rapidly, check out our blog post on yellow flag iris.

One of the methods to remove yellow iris is via mechanical removal, which entails retrieving as much of the root as you can, usually including digging and gentle pulling.

Native Blue Flag Iris [left] vs. Invasive Yellow Flag Iris [right]

an intern in waders removes yellow flag iris from a riverbank

Year Three of Yellow Flag Iris Removal

This year was the third year of yellow flag iris removal at Big McGraw lake hosted by Douglas county and Burnett county, and Wild Rivers Conservancy and the National Parks Service had the opportunity to join for a workday on June 16th. Going into an event like this, I had expected the invasive species to be everywhere and prepared for a long day of manual labor. While I was right about how difficult digging up yellow flag iris would be, I was pleasantly surprised with its minimal presence in and around the lake.

During the workday, we were assigned to remove yellow iris on the west side of the lake. However, by the end of the day we had just barely filled 3 trash bags. Zach Stewart, AIS/Natural Resources Specialist with Douglas County, said that in preparation for the first removal event in 2023 he had rated all patches of yellow flag iris on a scale of 1-5. A stand with a rating of 1 was made up of one or two plants, and a stand with a rating of 5 was a very large patch. In 2023, Zach recalls seeing everything from a 1 to a 5, but in 2026, he saw “nothing above a 3.” To me, that shows immense success, especially in a project that’s only in its third year.

Making a Difference With Partners

Of course, this success would not have been possible without the staff that put it together and the volunteers who come out each year to help. This event really gave me insight into the field of invasive species management. To dedicate your professional life to protecting our native ecosystems from invasive species requires a level of commitment and diligence that I truly admire.

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