Winter flowering weeds

Flowers in the landscape are usually a welcome sight, particularly at the beginning of spring. However, when those flowers pop up in unusual places, it can become cause for concern or confusion. After all, the definition of a weed is simply a plant growing out of place. With that in mind, I wanted to talk today about a common winter weed that is just starting to bloom.

Henbit, Lamium amplexicaule, is a weedy plant in the mint family (Lamiaceae).

This purple flowering weed is called henbit and over the next month you will be able to see it just about everywhere. It is a winter annual broadleaf weed. That is, it comes out during winter, flowers at the tail end of winter and early into spring, then dies off. The trouble is, before dying, it will set seed. Depending on how wind, water, birds or other animals move this seed, you will likely see henbit in your lawn year after year, though perhaps not in the same exact spot.  Because the

seeds are often carried by water, it is common to see patches of henbit in low areas in the lawn, or near ditches.

What you can or should do about henbit depends on a number of things. You may very well choose to do nothing. Henbit is a valuable food for pollinators, particularly honey bees, at a time when little else is in bloom, so if you don’t mind a few stray purple blooms amidst your yard, you may simply leave it alone. You can also mow it to knock it down and make it less noticeable if you’re not as keen on having purple blooms in the lawn, but this is something you’ll have to do repeatedly over the next several weeks and is really more of a delay tactic than a control measure.

Henbit flowers are whorled around square stems.

If you’re the type that is not willing to tolerate weeds in the lawn regardless of circumstance, then herbicides are an option, although now is not the ideal time to treat henbit with herbicides. Winter annual weeds such as henbit are best controlled by using a pre-emergence herbicide in the fall, similar to the way we treat for crabgrass in the spring. This is actually the best defense against these types of weeds, since it is much harder to kill them by the time they are flowering. Unfortunately, many people don’t think about the weed until it starts to flower, and by then pre-emergence herbicides will do no good. Make a note on your calendar in September to apply a pre-emergence herbicide for henbit and other winter annual weeds.

Hairy bittercress, Cardamine hirsuta

Other winter flowering weeds that are flowering now or will soon include hairy bittercress and chickweed (white flowers), speedwell (blue) and deadnettle (pink/red).  Because these are all broadleaf weeds, they can be treated in much the same way as henbit. Be sure to check the label to make sure the product lists the specific weeds you are trying to control, and follow the label directions for appropriate mixing and spraying directions. If you are unsure which weeds you have, you may bring a sample to the extension office for identification.

Chickweed, stellaria media

Speedwell, veronica arvensis

Deadnettle, lamium maculatum

The best defense against these weeds returning to your lawn each year is to grow a healthy stand of grass. While that sounds simple enough, growing healthy grass involves a number of different management practices, including proper watering, mowing, fertilization, and early detection and control of insect, disease, and weed problems. A healthy lawn will out-compete the majority of weed species.      
 
Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center.  If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardener Infoline at 252-902-1705.  

Photos: https://plants.ces.ncsu.edu