The 2025 editions of our Guides for controlling invasive knotweed are now available!  Sign up for access to the Guides at “Invasive Knotweed” on our website.  Here are the titles to the Guides:

• Knotweed Guide no. 1: How to control a small stand of knotweed.
• Knotweed Guide no. 2: How to control a medium to large stand of knotweed.
• Knotweed Guide no. 3: How to control a stand of knotweed with stem injection.

Some of the changes include the following:

• Advice on using our new Large Dispenser.  Our new Large Dispenser is highly versatile.  You can spray liquid spray drops or streams or dispense foam.  This flexibility will be especially helpful for those dealing with large stands of knotweed.
• Upping the percentage of herbicide used for foliar applications.  New research from groups led by Professors Mark Renz and Roger Becker at the University of Wisconsin and Minnesota indicates better success with these higher rates.
• Advice on applications during drought conditions.  Generally, we now recommend that you apply earlier if the knotweed stand is enduring a drought.  A drought may actually improve the performance of your herbicide application.