Getting Dirty to Protect Lime Lake

On Friday, June 21, we had another successful event digging for Yellow Flag Iris (YFI) in Pat’s Preserve on Lime Lake! Thank you to our volunteers who weren’t afraid to get their hands dirty!

Volunteers from left: Julie Doherty, Mark Fisher, Caleb Garone

Why do we dig up Yellow Flag Iris?

YFI is an invasive plant species in Northern Michigan. It does not have natural predators and is much hardier than its native counterpart- Blue Flag Iris- so YFI will out-compete Blue Flag Iris if they are growing together. Over the course of several years, one YFI plant will multiply and can take over an entire shoreline region.

Lake Biologist Kelsey Froelich and volunteer Bill Frank with several large clumps of YFI

How does Yellow Flag Iris reproduce?

The seeds from the YFI can float, so if they are dropped into the water, they will float down shore until they are washed onto land. YFI also reproduces via underground rhizomes (roots) with a central node. One plant can clone itself to make many new plants without using seeds at all.

YFI in bloom

How do we remove Yellow Flag Iris?

The easiest way to remove YFI is to dig it out. Make sure to get as much of the root mass as you can and any central ‘nodes’ (hard, pink-ish roots) that you can find. Once dug, it can be placed in a garbage bag and disposed of. If you dig YFI in an area that is directly on the shoreline, you may consider planting other native species in its place to hold the soil in place. Multiple years of digging may be necessary to fully eradicate YFI from your location.

Volunteer, Bill Frank

What is the lake association doing to combat Yellow Flag Iris?

Our lake biologist, Kelsey Froelich, conducts a YFI survey by boat in early June and locates all blooming YFI. She then reaches out to property owners that the Association has an email address to alert them of the sighting. Kelsey is also working with the Leelanau Conservancy to remove YFI from Conservancy property. Our goal on Lime Lake is complete eradication of YFI!

To identify YFI when there are no blooms, look for the prominent mid vein on the iris leaves

Are we making any progress?

Yes! We decreased our YFI locations by 6 sites in the past year and have dug with the Leelanau Conservancy for three years now. Last year, we replanted dig sites on Conservancy land with native Joe Pye Weed seeds, harvested from the Hatlem Creek Preserve (near Glen Lake) and we saw great growth in those areas this year!