Most of the landscape around is brown and has been for months now. Some weeds have been coming up since the fall that make the ground dotted with green. Let’s talk about these weeds and how to identify them. We’ll also discuss different ways to control them.
Henbit, common chickweed, and speedwell are all annual weeds. The issue with winter weeds is that they can slow down the growth of desirable plants in the spring. The winter weeds are bigger and stronger than other low growing plants early in the spring. This size advantage means they shade desirable plants around them and use the nutrients that are in the soil. This can lead to difficulties with summer weeds, because the winter annuals reduce the competitiveness of your desirable plants.
Henbit is a weed that is in the mint family, Lamiaceae. You can easily tell the mint family because the plants have opposite leaves and a four-sided stem. If you roll the stem between your fingers, you can feel the ridges on each side. The leaves for henbit attach directly to the stem. It has small pinkish-purple flowers at the top of the plant that are in a tube shape.
Common chickweed is another plant that has opposite leaves. Chickweed has small white flowers and is in the Caryophyllaceae family, commonly called the carnation family. It usually grows about 3-6 inches tall. The seeds from chickweed can remain viable for up to 10 years. There are a couple of different species of chickweed out there. Mouseear chickweed has hairy leaves and stems.
Speedwell is a clumping plant that has very small bluish-purple flowers. It grows in patches up to one foot in size. The upper leaves on speedwell are narrow, while the lower leaves are more rounded. It is in the Scrophulariaceae family, which is also the family that has weedy plantains. There are several different species of speedwell, but they all have the same general characteristics.
When controlling weeds it’s best to start by looking at your site. Knowing the pH and nutrients that are in your soil by taking a soil test through your local extension office is a good place to start. Then think about the drainage of your site. Sloped sites will drain more quickly. Does the soil need mulch to maintain soil moisture and add organic matter? If your site is in good condition and properly cared for and you are still having weed issues, then it might be time to start thinking about using an herbicide to control weeds.
It’s best to control Annual weeds in October with a pre-emergent herbicide. A pre-emergent herbicide is put down before weeds begin popping up. Post-emergent herbicides are used once the plant is already present and growing. Post-emergent herbicides can be effective if used when problems are noticed early. They become less effective as weeds grow in size. Pre-emergent herbicides containing the active ingredient benefin will be effective on henbit, chickweed, and speedwell. Benefin can be applied on established fescue and zoysiagrass lawns. Post-emergent herbicides containing 2,4-D + MCPP + dicamba can be sprayed on established fescue and zoysiagrass lawns as well. Whenever you apply an herbicide, make sure to read and follow the label before making the application.
If you have questions about winter weeds and how to control them contact your local Extension Office or send me an email at [email protected].