Henbit — The Purple Flower Weed

Last Updated on April 8, 2021 by Grow with Bovees

What Are The Weeds With Purple Flowers?

Henbit, (happily named because hens love eating it!) is a fuzzy little lawn weed with purple flowers and green to purple square stems. Plants typically grow 5 to 11 inches tall and have heart-shaped leaves that are veiny on the underside. 

Henbit – Lamium amplexicaule
Purple deadnettle — Lamium purpureum

The Difference Between Henbit and Purple Deadnettle

Because they are both in the mint family, look similar, and often grow in the same place at the same time, they can often be mistaken for one another. 

Henbit, (Lamium amplexicaule) has pink to purple flowers with purple spots, tubular and form at the end of stems in a small spiral formation. Henbit has rounded, scalloped leaves and only the lower leaves have petioles. 

Purple deadnettle, (Lamium purpureum) flowers are a lighter shade of purple and are fatter and shorter than those of henbit. The leaves are triangular with petioles and are increasingly purple towards the top of the plant. The leaves overlap and are also slightly fuzzier than those of henbit.

How Do You Treat Henbit – Pre-Blooms?

Carefully peruse your lawn to determine where the weed is growing, how much of your lawn is covered, and the underlying reasons why you have it.

Where to look? Henbit invades thin and weak parts of lawns and is often found in shady areas too, due to water not being evaporated efficiently. Henbit can grow in sandy soil but prefers to grow in moist conditions and areas where the turf has been damaged or stressed.  

You will not be looking for purple flowers at this point, in fact, inspection needs to take place before spring so that you can take action to kill the henbit before the blooms appear, therefore stopping the production of seeds.

Waiting too long to get rid of the henbit risks it spreading and getting out of control, which may take years to fix.

Henbit begins to wither in the hot summer temperatures and therefore germination begins from the seeds dropped as early as late summer. When plants are small and haven’t yet flowered, they can easily go unseen but, with careful inspection, they can be registered and dealt with. This is also the ideal time to kill them, as they lack toughness at this stage.

Once you know where the weeds lie (and why!), and after donning protective gear, and forewarning pets and family members to stay away, you can begin the process of henbit removal. In flower beds and landscaped beds, it can just be pulled up using a weed removal tool, and then mulch can be spread which will serve to suppress growth.

Control Of Henbit In A Lawn

For the rest, you will want to use a ‘post-emergent herbicide’, so first, find out if you have warm or cool-season turf and then choose the appropriate herbicide for broadleaf weeds. 

After calculating the size of the area you need to cover, and following the mixing ratios on the product you have, you can mix the herbicide and water up in a 1 – 1.5-gallon handheld sprayer. Pump until you have a low-pressure spritz of fine mist (you may need to adjust the nozzle to achieve this) and spray onto the weeds, taking care to miss the surrounding grass as much as possible.

Spray an even coating over the leaves until wet, but not soggy. You want the product to remain on the plants for as long as possible and not run off, be washed off, be blown off, or be licked off by the neighbor’s dog.

Check the weather beforehand, and try to do it on a rain less, windless day (or at least when winds are low speed) and when no rain is forecast for the following day.

You should see the affected weeds dying (wilting, going brown) around 2 weeks after application day. If you feel it is necessary, reapplication of the product can be done at this point, but keep in mind that herbicides contain strong chemicals, and usually labels restrict uses to just 2 in a one-year period. It may be best to exercise a little patience and discernment here, so as not to overdo it and kill your grass.

How Do You Treat Henbit – Post Blooms?

If you haven’t noticed your henbit problem until it has already bloomed, then it is best to use a pre-emergence herbicide treatment. This means instead of killing the plants you can see; you kill the possibility for future plant growth.

It is important to do this before the weather turns cool, so seeds don’t have a chance to sprout. Germination for this winter annual weed occurs about early fall so your pre-emergent treatment needs to be applied before this. Or else, before the soil gets cooler than 70 degrees F. Usually, you can find out average soil temperatures for your area to make planning this process a little easier.

This kind of product works by forming a chemical herbicide barrier, which stops seeds from sprouting. The best way to apply it is by spreading in parallel lines across the length of the lawn and then at a perpendicular angle, parallel lines across the width. When you have finished, water the area with at least half an inch of water.

How Do You Prevent Henbit?

Have a gorgeous, lush, thick, and healthy lawn! Yay! Henbit is a lover, not a fighter. If the grass is thick and lush, the henbit won’t fight it.

To achieve lushness, you need to make sure you are mowing your lawn at the correct height for your grass type and regularly feed it with lawn weed and feed every quarter.

Rake your lawn regularly and trim back overhanging shrubs, trees, and bushes to reduce moist shady patches in the garden, and improve air circulation.

Water the correct amount, that is, around 1 to 1.5 inches per week. When there is no rainfall this should translate to watering your lawn around once a week and preferably in the morning.

Finally, fertilize regularly with nitrogen, phosphorus, and potassium so that your lawn is strong, and weeds can’t get a look in!

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