Bert Swope
Armyworms are voracious herbivores that can damage your lawn within a few days. They feed on grass blades, causing brown patches to form along the perimeter and in the center of your lawn.
The best way to control them is to remove their eggs and larvae before they become large enough to harm your lawn. This can be done by removing thatch, regularly mowing grass, and applying pesticides.
Removing Thatch
A layer of dead plant matter (thatch) forms between the soil surface and the green grasses in your lawn. It is a natural, necessary, and beneficial part of the grass-growing process, but when it builds up to excessive levels, it can cause serious problems.
When a layer of thatch accumulates on the soil’s surface, it makes it hard for grass roots to absorb nutrients. This can result in your grass becoming more susceptible to pests and diseases.
You can tell when a layer of thatch is too thick by looking down into your lawn and seeing if there’s a matted layer of soil between the green grass blades and the soil below. If there is, you may need to dethatch the area.
Removing thatch can be done by hand with a rake or using a thatch dethatcher, a machine that combs through the grass and removes thatch. However, you should be careful not to rip the grass blades or damage the soil as you remove thatch.
The best way to prevent thatch is by establishing healthy soil conditions and improving lawn aeration. When the soil is aerated, it will encourage microorganisms that break down thatch and turn it into nutrients that improve the health of your lawn.
If you have a lot of thatch, aerating your soil will improve the air circulation in your lawn and allow water to penetrate into the root zone more easily. The holes left in your soil will also allow compost to seep into the ground and benefit your lawn.
Once aeration is complete, topdress your lawn with Soil3 compost to improve the aeration process and reduce thatch. The microorganisms inherent in our Soil3 compost will break down the thatch layer by consuming it and converting it into valuable nutrients for your lawn.
If you have an infestation of armyworms in your lawn, it is important to control them before they spread and take over your entire yard and lawn. The worms can be controlled with several methods.
Using Insecticides
Insecticides can help control armyworms in your yard and lawn. They work best if used early on when the armyworm caterpillars are small. However, they can also be harmful to birds and other wildlife. The key is to use these products at the right time of year and at the right application rate.
In general, insecticides kill pests by interfering with their natural ability to survive and reproduce. The type of insecticide you choose will depend on the pest in question, the size of your lawn, and other factors.
For example, you might use a broad-spectrum chemical to control armyworms, leaving beneficial insects like ground beetles and wasps alone. That can reduce natural enemies that prey on the pests, making them harder to control.
Another way to keep armyworms away from your lawn is to maintain it regularly. This includes mowing it regularly, removing thatch, weeds, and leaves, and fertilizing. Keeping your lawn at the recommended height reduces the amount of space that armyworms have to lay eggs and hide.
Mowing also reduces the number of armyworm caterpillars in your lawn and helps keep them from moving to neighboring grass. If you notice an infestation, mowing the affected area will kill off the caterpillars and prevent them from moving to other areas of your yard.
If you need a more targeted approach, you can use insecticides designed to kill only specific types of pests, such as Bacillus thuringiensis (Bt). These bacteria are natural to the environment and will not harm your plants or animals.
Applying Bt can be difficult if the weather is hot and dry, so you might need to wait until fall to apply it. You can also choose a liquid or powder insecticide, depending on the type of turf you have.
While you can spray insecticides directly onto your lawn, spreading them over the entire area may be more effective. This makes it more likely that the treatment will get into the soil where armyworms live and feed.
If you’re uncertain about using insecticides, the Environmental Protection Agency website is a good resource. It offers information on different types of insecticides, their active ingredients, and formulations. It also recommends using these products and other ways to protect plants from pests.
Applying Bacillus thuringiensis (Bt)
Using Bacillus thuringiensis (Bt) to control lawn insect pests is an effective and low-cost option. Bt is an earth microbe that produces a unique protein toxic to certain insect pests.
The type of Bt you choose depends on the pest you’re trying to control. Some varieties of Bt target specific pest groups, such as caterpillars and leaf miners. Other varieties are more broad-spectrum and affect other pests, such as flies, thrips, and beetles.
Bt is available in powder and a liquid form, which you can mix with water in a sprayer to treat weeds or the entire lawn. The amount you apply and the time between applications depend on the type of Bt you use and the number of insects you want to kill.
When you use Bt, read the label and follow directions exactly. You don’t want to kill beneficial insects, worms, or other nontarget organisms.
You should also be aware that some species of insects can develop resistance to a particular Bt toxin, so you’ll need to repeat treatments periodically if you have a problem. This can make it difficult to determine if Bt is controlling the pests.
Another pest control method involves entomopathogenic nematodes, microscopic insects that attack insect larvae. They’re safe for most pets and are a good option for those who prefer natural pest control methods.
Nematodes are most effective when applied to the lawn in a hose or backpack sprayer, separate from any pesticides or fertilizers you’ve used. It’s important to ensure the nematodes you use are fresh and haven’t been exposed to any pesticides, especially those that are causing harm to the environment.
Choosing selective, least toxic, IPM-compatible products is the best way to control pests and avoid damaging your lawn or the surrounding ecosystem. The best choices include microbial insecticides such as azadirachtin, pyrethrum (pyrethroids), and spinosad, which have minimal negative impacts on non-target organisms.
Neonicotinoids are also a good choice for controlling lawn insect pests, but they harm nontarget organisms and can interfere with surface water quality. These chemicals have also been shown to affect bee populations.
Handpicking Larvae
Armyworms are a problem in many areas of the country, especially the Southeast and Midwest. They feed on grass and other plant life in your lawn, causing damage by creating brown patches in your yard.
A good lawn care professional can help you get control of armyworms in your yard and garden. They may apply a granular fertilizer with a residual insecticide to help prevent future infestations.
Another good approach is to use beneficial nematodes, which work like invisible bodyguards walking around your lawn, destroying pests that cannot reach the root system of plants. This type of treatment is less toxic and safer for children and pets, because the nematodes are naturally present in the soil.
Other natural controls include keeping plants healthy and providing habitats that support beneficial insects. In particular, planting flowers and herbs nearby will attract pollinators to keep the pests away from your lawn.
Birds are also predators of armyworm moths and will eat larvae from your lawn and garden. They also will eat any eggs that they find.
Seeing many birds scavenging on your lawn could be an early sign of an armyworm population. In addition, small brown patches in your lawn or a ragged chewed edge on a grass blade can be a definite sign of an armyworm infestation.
These caterpillars are often green in color and can appear striped or spotted. They begin feeding in mid-May and cause circular bare spots in your lawn.
The caterpillars will then pupate in the soil. During the fall, you can turn the soil over to expose any pupae and make them easier for birds to eat.
During the spring, you can inspect your plants carefully and remove any adult caterpillars that are present. Doing so can save you a lot of time, money, and hassle in the long run.
You can also handpick any egg masses or larvae that you see. This is a more effective strategy than spraying chemicals, which can cause more damage in the long run.
