I am wondering if help is available to address the concern on private property. If not, any advice for managing it myself would be appreciated.

I also continuously battle ivy on this property.

Reporter
May 21, 2013, 3:33 a.m.

Thank you for taking the time to report this. Unfortunately, since yellow flag iris is quite common in the Willamette Valley it isn't the focus of many treatment programs. They typically focus on a few high priority plants - those that have not yet gotten as wide-spread (i.e. Japanese knotweed, giant hogweed, and garlic mustard). But I am forwarding your report to Clean Water Services, in the hopes they might be able to assist (assuming they have the budget for it) in some fashion.

For information on managing it yourself, I encourage you to read through the King County, Washington Best Management Practices for this invasive (http://your.kingcounty.gov/dnrp/library/water-and-land/weeds/BMPs/yellow-flag-iris-control.pdf). There are many techniques to remove YFI, but they are often difficult unless it's an isolated patch that can be dug out. At the least, I'd would strongly encourage cutting all the flower heads before they form & disperse seeds (bagging the seeds for disposal in the trash - NOT with your yard waste).

Thank you for keeping and eye out on your neighborhood waterways and for reporting your find!

Best of luck,

Vanessa Morgan
Portland State University, Center for Lakes and Reservoirs

Vanessa Howard Morgan
May 21, 2013, 7:25 a.m.