I’ve received a few questions asking what the purple weed is that is appearing in the landscape. It is probably either purple deadnettle (Lamium purpureum) or henbit (Lamium amplexicaule).
These weeds often get confused because they look similar. They both belong to the mint family, have square stems, have an ascending growth habit, opposite leaves, purple/pink flowers, and are winter annuals. When trying to identify if you have purple deadnettle or henbit, key ID traits to tell them apart are listed below.
Key ID traits for purple deadnettle:
- Purple-tinged leaves on upper stem triangular with pointed tips
- Upper leaves with petioles, not directly attached to stem
Key ID traits for henbit:
- Leaves rounded with deep lobes and venation on upper stem
- Upper leaves directly attached to stem with no petioles
- Densely pubescent (hairy) leaves
Since both are winter annual, preventing seed production is key to management. Tillage and herbicides are effective management options for these weeds. Both species are flowering now and management with herbicides will not likely result in full control. Fall or early spring herbicide applications will be most effective at managing problem infestations. Contact your local Iowa State University Extension & Outreach field agronomist for resources regarding control of these weeds.
Another weed that belongs to the mint family and is making lawns appear purple right now is ground ivy (Creeping Charlie, Glechoma hederacea). Unlike henbit and purple deadnettle that are winter annuals, ground ivy is a perennial weed, and also generally stays confined to lawns.
t appears that winter is giving up its grip, and spring is starting to take hold here in Tulsa. Temperatures are moderating. Trees are beginning to bloom and leaf out. Fescue lawns are getting to be a darker green. And all around town, you can see the blooms of henbit turning area lawns purple.
Henbit, an annual winter weed, is a member of the mint family. If you rub the stem of these purple flowers between your fingers, you will find that it has a square-shaped stem and minty smell. Left untreated and un-mowed, these weeds can grow 12 inches or taller, while producing many purple flowers. Like all weeds, henbit competes with the healthy turf for resources in the soil and can leave your lawn in pretty bad shape.
The best means of control for these purple flowers, and other winter annual weeds, is to apply a fall pre-emergent weed control. The fall application will provide a layer of protection in your soil that will not allow weed seeds to grow into difficult to control plants. However, if you missed the fall pre-emergent, these winter annuals can be controlled with a post-emergent.
Post-emergent weed control in the spring can be a little slow in the killing process, mainly due to cooler temperatures. While the plant will absorb the post-emergent and the weeds will begin to die, the process can take several weeks. The best thing you as a homeowner can do is mow the weeds down within five to seven days of our application. This will speed up the decomposition process and help your lawn begin the process of looking better quicker.
If your lawn is full of these purple weeds, or any other weeds, give us a call at 918-844-0043! We can help get your lawn head in the right direction. We can also help your neighbor, too! Refer a friend or neighbor, and we’ll give you $30 off your next application and give your neighbor $30 off their first application, too!
Maintaining a healthy lawn starts with proper nutrition, but it also requires careful weed control. Sure, you can buy a generic weed killerand throw it on your yard with some success. If you want to increase your success at killing every weed in your lawn, being able to identify them and using the proper weed control formulas is critical.
Our weed identification guide will give you a leg up in eradicating those nutrient-draining eyesores for good and getting the lush lawn you crave.
Wild Violet
Wild violet is a perennial weed that is relatively easy to identify thanks to the bright violet or blue flower it produces and its heart-shaped leaves. It is a low-growing weed that is generally less than a foot off the ground.
Where Wild Violet Thrives
Wild violet grows the strongest in moist, shady areas and spots where grass coverage is thin. Though it prefers moist soil, wild violet can survive drought once it’s established.
How to Control Wild Violet
The best way to control wild violet is by creating a thick, healthy lawn. As mentioned above, wild violet prefers areas with minimal grass coverage, and a thick carpet will present a challenge to fledgling sprouts. Pre-emergent weed treatments are not effective on wild violet.
If your lawn has existing wild violet weeds in it, you can remove them through manual pulling. Simply moisten the soil and pull upward sharply until the weed and its root release from the soil.
If you prefer to go the chemical route to rid your yard of wild violet, you can use a post-emergent herbicide containing 2,4-D; MCPP; dicamba; or triclopyr.
Wild Onion and Garlic
Wild onion and garlic are perennial weeds with a grasslike appearance, making them harder to spot. But you can identify them by their distinct upright stance and small, white flowers in more mature weeds. They are also easy to identify by their strong onion and garlic odor.
While they have the same basic characteristics, you can identify distinguish wild garlic by its cylindrical and hollow leaves. Wild onion’s leaves are flat and not hollow.
Where Wild Onion and Garlic Thrives
Wild onion and garlic are hardy weeds that can grow in a wide range of soil types and conditions. They can also survive cold and drought, making them a particularly frustrating weed.
How to Control Wild Onion and Garlic
Unfortunately, pre-emergent herbicides don’t affect wild onion and garlic. A thick lawn is the best preventative measure, but it doesn’t guarantee you won’t have a few patches crop up.
Manual removal is possible, but do not attempt to pull wild onion or garlic by hand. The bulb at the base of the plant will break off when you try to pull it by hand, and it will grow back quickly. Instead, use a small shovel or spade to dig up the bulbs, which are generally at least 6 inches deep.
You can also take the chemical approach by using post-emergent herbicides like 2,4-D, MCPP and dicamba; metsulfuron; sulfentrazone and metsulfuron; sulfosulfuron; or glyphosate.
Dandelion
Dandelions are some of the most common perennial weeds in the U.S. They crop up in the spring and seem to spread like… well… wildflowers. They are relatively easy to identify with their 1- to 2-inch-wide bright-yellow flower, semi-hard 6- to 24-inch stem and toothed leaves.
Unlike many lookalike weeds, dandelions only have one stem and one flower per plant – if it has multiple offshoots, it isn’t a dandelion.
Where Dandelions Thrives
Dandelions are a hardy weed that grow in various conditions, but they thrive in moist, sunny areas.
How to Control Dandelions
To prevent dandelions before they ever grow, you can apply a pre-emergent herbicide in the late winter. Applying it then prevents the seed from germinating. If you apply it any later, the dandelion will still break the surface and take over your yard.
If you already have a dandelion problem, you can use a selective post-emergent broadleaf herbicide to kill each plant individually.
Prefer to go the chemical-free route? You can also remove dandelions by hand using a dandelion removal tool or by simply digging up the taproot. Dandelion taproots are very long, so make certain you get it all. Leaving just one piece of the root intact can lead to even more dandelions.
Garlic Mustard
Garlic mustard is a biennial weed that generally grows 2-3 feet tall but can reach 6 feet in some cases. You can identify garlic mustard by its kidney-shaped hairless leaves with scalloped edges, its S- or L-shaped root, four-petal white flowers in the spring and distinct garlic smell.
Where Garlic Mustard Thrives
Garlic mustard prefers disturbed soil with plenty of shade but will sometimes invade areas of full sun.
How to Control Garlic Mustard
There is no known pre-emergent weed control for garlic mustard, but it is otherwise relatively easy to control manually or chemically.
You can manually remove garlic mustard by gripping it firmly at the base and pulling upward sharply until the plant and root are free of the soil. Because its seeds spread easily, immediately put the pulled weed in a bag or trash container.
If you prefer the chemical route, you can apply a post-emergent herbicide containing glyphosate; triclopyr; 2,4-D; metsulfuron or oryzalin. Use care around other grasses, as some post-emergent herbicides can kill it.
Canada Thistle
There are many varieties of thistle, but one of the more common types that invade our lawns is Canada thistle. You can identify this 3- to 5-foot-tall perennial weed by its deep-lobed lower leaves, more toothed upper leaves and lavender, pink or white flowers.
Where Canada Thistle Thrives
Canada thistle prefers wetter, disturbed grounds like ditch banks, pastures and tilled fields, but is no stranger to backyards.
How to Control Canada Thistle
Canada thistle is an invasive species that can create havoc in your yard, so it’s key to eradicate it as soon as you identify it.
There is no known pre-emergent herbicide for this weed, and the control process requires several seasons’ worth of treatment. In the late spring, you must apply one treatment of glyphosate and one treatment of dicamba and 2,4-D. In the fall, you will make five treatments, including one of each of the following herbicides:
- Aminopyralid
- Aminopyralid and 2,4-D
- Chlorsulfuron
- Glyphosate
- Dicamba
Do not attempt to pull Canada thistle, as this can cause a split root, which can sprout two new plants.
Broad-Leaved Dock
The broad-leaved dock is a tall perennial weed that grows up to 3 feet tall from a rosette base. You can identify it by its long, broad leaves with pointed tips and wavy edges. The leaves near the base of the weed are significantly larger than those near the top and generally grow in an alternating pattern up the stalk.
As you near the top of the plant, the broad-leaved dock features a series of seed pods that are about a tenth of an inch long and light brown.
