I have this weed taking over a spot in my St. Augustine grass. What is it and how should I get rid of it. Warm climate in South Florida.

photo of unknown weed

It seems to have small blueish flowers and the roots are really able to choke competition. Looking to do some post emergent too. Don't want it coming back.



Here it is in the ground.

photo of unknown weed in the ground

Another better view:

another photo of unknown weed

  • Can you give us a picture of the weed as it is growing, and also reverse the orientation of the existing image? Jan 10, 2017 at 22:56
  • I wonder if it's one of the Tradescantia Jan 11, 2017 at 0:06
  • I am thinking Veronica or Speedwell. Which thrives with low mowing heights.
    – stormy
    Jan 11, 2017 at 2:27
  • Added another close up view. @stormy. If you write up an answer with some herbicide recommendations to be used in St. Augustine turf grass I can mark it accepted.
    – Mike
    Jan 11, 2017 at 2:33
  • OK...wandering jew...Graham?
    – stormy
    Jan 11, 2017 at 2:36

1 Answer 1


It's Commelina diffusa (aka communis). Some advice for control: PDF

And here: Asiatic Dayflower The Little Beauty that Caused So Much Confliction

Wikipedia: Commelina diffusa, sometimes known as the climbing dayflower or spreading dayflower, is a pantropical herbaceous plant in the dayflower family. It has been introduced to the southeastern United States where it is most common in wet disturbed soils. There are two recognised varieties, one being the type and the other being C. diffusa var. gigas, which is native to Asia and has been introduced to Florida. It flowers from spring to fall and is most common in disturbed situations, moist places and forests. In China the plant is used medicinally as a febrifuge and a diuretic. A blue dye is also extracted from the flower for paints. In the Hawaiian Islands, it is known as "honohono grass", although it is technically not a grass. "Honohono" refers to the alternating structure of the leaves. At least one publication lists it as an edible plant in New Guinea.

Full Wikipedia article

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  • Can you provide a synopsis for the link you offered for quick reference?
    – Mike
    Jan 11, 2017 at 3:08
  • Sure. See edit.
    – Brenn
    Jan 11, 2017 at 3:11
  • If you're referring to the article about eradication, the PDF, it's best to download it. It's lengthy,
    – Brenn
    Jan 11, 2017 at 3:21
  • I attempted to post the contents of the PDF as a comment but the justification was all over the place. Try the PDF, most newer mobiles should be able to parse it.
    – Brenn
    Jan 11, 2017 at 3:29

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