What is that Yellow Flower?

Much of Comanche and surrounding counties have been invaded by yellow flowers. These flowers are especially prominent in pastures and hay fields. While there are lots of yellow flowered weeds, most of what we are seeing is Texas Groundsel, often called Texas SquawWeed or Tansy Mustard. Squaw- Weed is typically seen more in hay fields and the Tansy Mustard in ditches and other undisturbed areas. Both can appear most anywhere, but they really like our sandy soils. What little rainfall we have had, has resulted in the abundance of these plants, as well as many other spring annual weeds.

We have all been happy to see something green this spring. While the yellow flowers are pretty, both yellowed flowered plants are considered toxic to cattle. The Squaw-Weed is a little more toxic than the Tansy Mustard which is only moderately toxic. Poisoning of cattle with both species is uncommon and can be reduced by providing hay and supplemental feed. Cattle would typically only graze the plant during the rosette stage, and then only if hungry. All our cattle have been hungry this year, but no reports of any livestock deaths from either plant this year have been heard of. Both plants are now out of the rosette stage, and it is unlikely cattle will graze them anymore this year. Goats and sheep will help control them in rangeland and pastures without any negative effects.

While it is really too late this year, you can easily manage the plants with an application of 2,4-D while they are still in the rosette stage. An application of glyphosate in mid-February on hay fields will also get rid of them and other winter annual broadleaf and grassy weeds on hay meadows. At this point you can just leave them and let them die in a couple of weeks or shred them. Any weeds can be an issue, but we typically see large populations like this after some rainfall following drought periods. Let us hope we have more weeds to deal with throughout the summer as a result of good rainfall.