Knowledgebase
I want to identify a resistant weed that is spreading in the lawn #869228
Asked May 20, 2024, 11:14 AM EDT
Hello from Billings MT. USA.
I have a lawn invader that is resistant to 2- 4D and leafy, like a leaf of a tree. Slightly serrated margins, fuzzy pistiole that was lush green and now turning a bit purple. slightly stiff midrib, easily visible veins and the venules are very light, as in harder to see. The leaves start curled and eventually flatten, but not all the way and seem to grow singular and two to three off one "stem". I first noticed them last year and paid little mind to the small area where they were located, but this year it is clearly spreading. Roundup for lawns is the product I used on them and I belive I heard them laugh at me. I treated them twice since spring started along with Scotts plus dandilion and crabgrass control. Any ideas of what it may be? The closest I found to leaf structure that I have found was Blue Violet, but I am almost certain it is not that.
Yellowstone County Montana
Expert Response
The growth habit and appearance of the leaves make me think it could be common burdock (Arctium minus) or one of the docks (Rumex species).
All have a rosulate growth habit - their leaves form a basal rosette, which fits your description of two or three leaves growing from one stem. They never get big because I imagine you mow regularly. Burdock is a biennial, which means it lives for two growing seasons; the docks are perennial.
Both species are listed as controlled on the Roundup for Lawns label. It does not contain 2,4-D, but the Scotts product does. In my experience, liquid herbicides are more effective than granular products. Perhaps something that contains 2,4-D, MCPP, and dicamba would be more effective. Spectracide Weed Stop for Lawns, Fertilome Weed Out Lawn Weeds Killer, or Ortho Weed B Gone are liquids that contain those active ingredients.
Best regards,
Sandy
