It’s spring, finally! I know our winter wasn’t terrible this year, but I always look forward to spring. That is such an exciting time of the year, all of our plants are greening up and the early blooming trees, shrubs, and bulbs are beginning to show us their beauty for the year. However, not everything about spring is fun and games. This is the time of the year I always get calls about that dreaded purple flowering weed in our lawns and gardens.
Henbit is the purple blooming weed that shows its ugly face very early in the spring. This is the weed that will cover crop fields early in the spring with large expanses of purple blossoms. This weed is also quite prevalent in our lawns and gardens.
Henbit is a member of the mint family, which means that it has square stems. It has leaves that are rounded with a scalloped edge and they are arranged oppositely along the stem. It has a small purple flower with darker colored purple spots on the lower petals of the flowers. Henbit is often confused with creeping Charlie or ground ivy, which is a perennial weed from the same family with purple colored flowers as well. The differences between the two are that creeping Charlie is a perennial so it blooms later in the year than henbit and creeping Charlie has flowers that are more blue and henbit flowers are more purple.
Henbit is a winter annual. This means that henbit only lives for one growing season, but it’s development is different from something like crabgrass which is a summer annual. A winter annual is a plant that germinates in the fall and grows a bit before basically becoming dormant for the winter months. Very early in the spring, henbit will start to grow again, produce flowers which produce seed for the growth to come next year and then it dies. A winter annual dies as soon as the weather starts to warm up in the late spring whereas a summer annual germinates in the spring and goes through it’s lifecycle through the summer months, dying with our fall frosts.
The problem with henbit is that by the time we see it, or rather see the beautiful purple flowers, it is too late to treat it this year. As I said, henbit dies when the weather warms up, so why spray it with a chemical when it is going to die in a few weeks anyway. The fact that it is noticed when it is blooming shows us that it is already producing seed for next year, so killing the existing plants does nothing for the future generation of this plant. However, pulling the plant would be a fine management practice in the spring months.
Henbit is a plant that tends to grow in the areas where grass typically dies out. Areas around sidewalks and driveways or areas where people tend to cut the corner around sidewalks are locations where the turf gets worn down and the henbit excels. Henbit is also often found along the foundation of a house or in a garden area with exposed soils. If we can do things to keep your grass growing in these locations or use other plants or mulch to cover the bare soil, the henbit will struggle. Using a pre-emergent herbicide for broadleaf weeds in the fall will also help reduce the seed germination. Finally, using any broadleaf post-emergent herbicide later in the fall after the henbit has germinated, such as 2,4-D, will kill henbit as well.