Good Weed, Bad Weed

By Lloyd Singleton, Extension Agent II

A Lake county resident recently contacted our Extension office with a photo of a “weed” that she thought looked like the one taking over her shady St. Augustine lawn, wanting to know how to get rid of it. I was easily able to identify the plant in the photo as Oplismenus setarius. The name just rolls off the tongue, right? Well, perhaps you’d prefer to use one of the common names, Woods grass or Basket grass when you refer to this underappreciated, native-Floridian, shade-loving groundcover.

What to do with Woods grass weeds?

Woods grass is appreciated for its tolerance of deep shade and our rainy summer months. By winter, the woods grass will subside. In the meantime, there is no selective herbicide appropriate to use in turf, so I recommended one of these three actions:

  • Hire an arborist to appropriately thin the trees and increase sunlight to the area
  • Mechanically remove the woods grass where unwanted (weed pulling)
  • Appreciate the natural beauty of this native groundcover until winter dormancy
Skunkvine weed?

Given my recommendation, the resident looked more closely at the photo she sent, and realized that it was not the weed in her turf after all. She followed up by sending actual photos of the weed, skunkvine (Paederia foetida). If she breaks off a few leaves and crushes them, it should have a strong sulfur-like smell. It is a Category I invasive in Florida and is a bad one!

Bad Weed, skunkvine

Bad Weed, skunkvine

Skunkvine leaves can vary in appearance depending on where it is growing and the age of the plant. These were fairly young and in a relatively shady spot, probably with a tree or some shrubs nearby that also have skunkvine growing in them; that is where we usually see it growing in turf. It roots all along the stem, especially at the nodes and can become quite woody. When it gets woody, it is more difficult to control.

There are several broadleaf herbicides that can be used for control but the best one would depend on where the skunkvine is growing in relation to other shrubs, trees, or etc. The products available to homeowners change quite often; availability also varies by location and retail vendor. The best thing to do for most homeowners would be to call a lawn control professional to handle it. It will probably take a few applications for complete control and it still might come back, so it is important to maintain an eye on the area once it seems to be gone.

Our UF/IFAS Extension weed specialist, Chris Marble has tested herbicides on skunkvine, and the only ones that have been effective are either non-selective (like glyphosate) or can’t be used in St. Augustine (like triclopyr). He reports that several professional pest control companies have had success with different rates of metsulfuron (Manor, MSM, etc.) but that is a pretty powerful herbicide in terms of what it could do to non-target plants and should only be applied by someone who is trained (although it’s not restricted to just professional use).

The moral of the Good Weed, Bad Weed story? Make sure you know what plant you’re dealing with, and UF/IFAS Extension is here to help. Visit our Master Gardener plant clinic at 1951 Woodlea Road, Tavares, Monday through Friday, 9 a.m. – 4 p.m.

6 Comments on “Good Weed, Bad Weed

  1. The non-native species Oplismenus burmannii (Burmann’s basketgrass) is now increasingly common throughout Central Florida. It looks very similar to the native Oplismenus setarius. The two species can best be distinguished by examining a flowering sample under a microscope (O. burmannii has flowers with awns that have downward pointing sharp hairs, while the awns on the flowers of O. setarius are hairless).

    Note that not only is skunkvine (Paederia foetida) at FLEPPC Category I invasive, it is also on the Florida noxious weed list, which means it is so invasive that it is prohibited by law. Early intervention is really helpful in getting this aggressive noxious weed under control.

    Marc S. Frank
    Extension Botanist
    UF/IFAS Plant Identification and Information Service
    University of Florida Herbarium (FLAS)

  2. Is there any information on how it’s propagated and how prolific it is… Could it be contained somewhere in a landscape at a distance without popping up everywhere?

  3. How can I get rid of a weed taking over the lawn, that looks like a wild version of alyssum, a common bedding annual? I live in Lady Lake FL.

    • Send a photo to the extension office or bring in a sample for ID. It is probably a broadleaf weed that can be treated with a selective herbicide that will not harm the grass in the lawn.

  4. Please link to photos of flowers from Burmann’s and native to facilitate identification.

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