Henbit?!

Henbit from canva

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, steve dewey, Utah State Univ, Bugwood

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.

Spring Lawncare

Spring Lawncare, blog post

April is finally here, which means spring should be bringing in warmer weather. April is a good time to get out and start working in the lawn and garden to prepare our yards. To help ensure that you have the best lawn on the block, here are few tips to improve your lawn this spring.

April is a great time to overseed your lawn. If you had some spots that were flooded out last spring, now is a great time to get some new seed planted. The beginning part of April is best for seeding lawns, but it can be done until the end of the month. Frequent, light irrigation is necessary to keep newly seeded lawns moist. It may be necessary to water twice a day to keep it from drying out and dying. Straw mulch can be applied to keep the seedbed moist, but it is not necessary and can bring problems with weed seed that is often a contaminant of straw. Do not apply any pesticides to newly seeded lawn until you have completed 2-3 mowings. Also, do not try to overseed right before or right after applying crabgrass preventer as this chemical will prevent the germination of your desired grasses as well.

We often face difficulties with weeds in our lawns. The key to weed management is to keep your lawn healthy to avoid weed infestations and to identify the weed before chemical controls are used. Many of our herbicides are specific to either a grass weed or a broadleaf weed and won’t work on the other weed type. Also, you need to know the weed to know the lifecycle for when the best time is to manage that weed with a chemical. As I stated in my previous news column, henbit is a winter annual and should only be chemically controlled in the lawn in the fall, the spring is too late.

crabgrass, Joseph Berger, Bugwood

Crabgrass Photo By: Joseph Berger, Bugwood.org

Crabgrass pre-emergent herbicides need to be applied before crabgrass germinates, which is when the soil temperature is 55-60 degrees Fahrenheit. This typically occurs toward the end of April. Applying this chemical too soon may cause the chemical to stop working earlier in the season when crabgrass may still be germinating. In this case an additional application may be necessary later in the spring, so it is best to wait until the correct time to only have to apply this one time per season. Broadleaf weeds, such as dandelions, clover, and ground ivy should be controlled in the fall for best control but can be managed in the spring with 2,4-D products.

Fertilizing turf can be done up to 4 times per growing season. Apply fertilizers at a rate of 1 pound of nitrogen per 1,000 square feet for each application. A good trick for remembering when to apply fertilizers is to fertilize with the holidays: Arbor Day, Memorial Day, Labor Day, and Halloween.

Mower Collage

We are now getting to the time of year when we will have to start mowing our lawns. Prepare your lawn mower for the season before you start mowing. Start by sharpening the blades. Dull mowing blades can cause tearing to occur on the grass blades rather than a smooth cut. These tears can lead to more insect and disease problems. Change the oil in your lawn mower, if you didn’t do that in the fall. Check your spark plugs and tire pressure. Finally, make sure you clean under the deck for any grass that may still be stuck under there from last season. You can start mowing as soon as the grass starts growing. Remember to mow at a height of 2.5-3.5 inches and only cut off 1/3 of the grass blade each time you mow.

Henbit in the lawn

Henbit flower from canva

This time of the year is always fun. It is starting to warm up and we can begin to emerge from our winter hibernation indoors. However, with the movement outdoors come the calls to my office. People venture outdoors and begin to notice plants growing that were not intentionally planted. One of the most common nuisance plants that seems to plant itself in your beautiful lawn and is noticed early in the spring is Henbit.

Henbit is a plant in the mint family and therefore it has square stems. It grows to a height of 16 inches and has dark green leaves that are scalloped along the edges and arranged oppositely along the stem. The leaves are clasping below the flower cluster. It has a purple colored, tubular flower. This is a plant that spreads by seed but can quickly invade turf areas and invade into a flower or vegetable garden. Henbit is the plant that is often seen in masses of purple in fields very early in the spring.

Henbit in field from Purdue

Cornfields full of purple henbit (Purdue Agriculture photo/John Obermeyer)

Henbit is a winter annual plant, which means that it germinates in the fall or winter. It then grows for a period of time in the early winter, goes dormant in the very cold periods and resumes growth early in the spring to flower and produce seed. After flowering, it will die, because it has set seed for new plants for next fall and spring.

People typically only notice henbit in their lawns in the spring when it is flowering. However, the best time for management is in the fall when it is first germinating. If you use chemicals to control henbit in a lawn, it is best to do prior to flowering and seed production. In the spring, when most people see henbit, there is no need for chemical controls because the plant has already set seed for next year’s crop and the plants seen are on their way to death anyway.

Management can be successful without chemicals. Henbit is a plant that does well in the areas where our turf does not. It grows well in compacted soils, typically along the edges of sidewalks and driveways where it can easily outcompete our turf for the space. It also grows well where there is good soil moisture and shade. Because of this, it is easily managed by encouraging a dense, vigorous turf or to change the landscape by utilizing other plants besides turf or applying mulch in areas where turf struggles and henbit grows well. Henbit can also be hand-pulled for quick removal, this is the preferred method of control in the spring. If chemicals are necessary and desired for management of Henbit, they should be applied in the fall. Products that contain 2,4-D have the best control for Henbit.

henbit, steve dewey, Utah State Univ, Bugwood

Photo by: Steve Dewey, Utah State University, Bugwood.com

Henbit is often confused with Creeping Charlie, or Ground Ivy, because they are in the same family of plants and they both have similar flowers. Henbit is a winter annual, while Creeping Charlie is a perennial, so henbit will flower well before Creeping Charlie does in the spring. Also, Creeping Charlie tends to have more blue flowers while Henbit has more purple-lavender flowers. Henbit has clasping leaves below the flower cluster, while Creeping Charlie does not. Be sure you know which plant you are dealing with to achieve the best control.