Kansas State University


K-State Turfgrass

Knotweed – Last year it was April, Now its February!

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Last year I did one of my first Turfgrass Selfie Series on knotweed control in April.  The knotweed had germinated and started to mature.  Just a couple weeks ago I was walking into my office and I saw knotweed already germinating.  (See picture below – Photo taken Feb. 22, 2017)

So needless to say.  If you didn’t get your preemerge out and you have a history of knotweed it is time to go out and attack the knotweed and other broadleaf weeds you have lingering around.  These weeds are easier to control now when they are young compared to when they get mature.

Below is the Knotweed Control Turfgrass Selfie Series Video I did last year but here are the take home messages;

  • Early germinating summer annual
  • Likes compacted soils/flooded areas
  • 2,4-D = fair control
  • 2,4-D + triclopyr or dicamba = excellent control
  • metsulfuron can be used in warm-season turf
  • PRE applications must be done in the Fall

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

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