Knowledgebase
Lawn weed identification #840170
Asked July 11, 2023, 5:39 PM EDT
I am trying to identify this invasive lawn weed and learn how to eradicate it. Although it looks like Spurge, it doesn't grow in a circular or radial pattern. This weed grows laterally in long tentacles; sometimes the tentacles are many feet long. The root is very difficult to remove and also grows laterally, rather than straight down. It ends up killing the grass, especially St. Augustine, and when it begins to invade healthy grass, it is difficult to see until a pinkish/purple flower head appears. Thank you.
Tarrant County Texas
Expert Response
Thanks for your message,
I’m familiar with common turf grass weeds in this area, but your picture stumped me. It looks as though it may have come from a native area rather than being a common turf grass weed. A search led to two sites shown below, but I don’t believe either correctly identifies your weed. In reality, the exact ID of your weed is not important. If we put aside nutsedge for the moment, then there are only two weeds—broadleaf and grassy weeds. https://aggieturf.tamu.edu/turfgrass-weeds/
https://aggieturf.tamu.edu/turfgrass-weeds/
https://i.etsystatic.com/24093067/r/il/791a79/<personal data hidden>/il_794xN.<personal data hidden>_bx0z.jpg
Your weed appears to be a broadleaf weed, so you would need to apply any broadleaf herbicide and, on the ingredients, listed on the label you would see 2,4-D among other listed items. You might add a drop or two of liquid dish wash soap so that it would stick to the leaf. The weed is killed by the active ingredient being absorbed through the leaves—NOT a root uptake.
Your weed would not “kill†St. Augustine, but it might crowd them. I could not see the root of your weed, but it appears to be one with a single source rood. As woody as it is, it would seem that pulling it up by the root would be effective, but I believe you indicate this has been tried unsuccessfully. Your weed does not appear to have much leaf surface for the 2.4-D to be absorbed, so it may take several applications.
Hope this helps,
Rick Williams
