Buckthorn fungus?

Asked May 30, 2017, 4:00 PM EDT

Hi, I am constantly battling buckthorn on my Washington county property (Grant, MN). I noticed last weekend that almost all of it has a kind of orange growth/fungus on the leaves. I do not poison it (just persistently hack it back), and I do not use any chemicals on my rustic "lawn". My hope is that it is a permanently debilitating disease that kills just buckthorn and will eradicate all my buckthorn (and all my neighbors' buckthorn) with no further effort on my part. Of course, I know nothing, but a boy can dream ... I wonder if you all might comment? I've attached a couple pictures, and please feel free to contact me at 612.868.5807. Happy to send a specimen. With Gratitude, Fritz Bergmann

Washington County Minnesota

1 Response

Thank you for the question. Another expert has diagnosed the buckthorn as being infected with oat crown rust, and the rust is very heavy this year. Buckthorn is the alternate host for oat crown rust which means that this is an infection of oats that requires buckthorn to complete its life cycle. Read the details here:

It's doubtful that it will kill the buckthorn and you will have to continue your control measures. Here is the University of Minnesota publication on buckthorn control: https://www.extension.umn.edu/garden/yard-garden/weeds/buckthorn-control/

Thank you for contacting Extension.