How to Control Henbit in the Lawn
Henbit is a cool-season lawn weed common in the South. It's a member of the mint family, and exhibits characteristics of other mint family plants, including the square stem that all mint relatives have. If you're trying to determine whether a weed in your lawn is henbit or something else, the first thing to do is feel the stem. Is it round or does it have edges? If it has edges, and it meets all of the other characteristics, it's probably henbit.
Do you need to control henbit in your lawn? That's up to you. Because it's an annual, it doesn't persist from season to season. It's more of a nuisance than anything.
Characteristics of Henbit
Henbit is a cool-season annual, so you're most likely to see signs of it from September through May. It's a broadleaf weed, which means it has larger leaves (not grass-like) leaves. Leaves closest to the top of the plant attach directly to the stem. Lower leaves have petioles (leaf stems). The most defining characteristic of henbit is its hook-shaped tubular purple flowers, which the plants produce during warm winter days. The plant's growth habit also gives it away: it tends to crawl along the ground, rooting into the soil from places along the stem. If you see a dense mat of green with the purple flowers sticking up, you most likely have henbit.
Cultural Control of Henbit
Many annual weeds respond favorably to mowing. If you cut off the plants before they can flower and set seed, you can easily control the spread. Not so with henbit, because of its close-to-the-ground growth habit. It grows so low that mower blades won't touch it.
The better way to control spread of henbit is to establish a dense, healthy turf. If the plants can't reach bare soil, they won't root in. Henbit also thrives in moist areas. If turf is dormant during the winter, you shouldn't be watering it anyway. For areas planted with cool-season grasses that grow during the winter, if you notice henbit encroaching, cut back on watering.
Chemical Control of Henbit
There are various lawn chemicals labeled for control of henbit. The type of chemical you use, the amount, and the timing of the application all depend on the type of lawn grass that you have. Check with your local cooperative extension to see what they recommend and when they recommend application. Always read and follow instructions on the pesticide label to ensure your safety and the safety of others in and around your lawn.