Insect Control in Your St. Augustine Lawn

St. Augustine’s a beautiful grass found throughout the majority of Florida home lawns as well as many residential and commercial landscapes in the southern two-thirds of the United States. However, it’s just as vulnerable to insects as other warm season turfgrasses. St. Augustine is loved for its remarkably thick grass blades that form a really dense canopy over lawns. It’s beautiful, tropical-like appearance makes for a gorgeous lawn with high curb appeal.

St. Augustine can experience a range of different lawn pests and insects though. Given the right amount of time, these insects and grubs have the ability to completely devastate a lawn leaving nothing but discolored, damaged, or even dead grass in its place. Arming yourself with the knowledge to identify, prevent and treat them will help you keep your St. Augustine lush and thriving.

Common Insects in St. Augustine Grass Lawns

Some of the most common insects found in St. Augustine lawns are chinch bugs, fall armyworms, sod webworms, billbugs, grub worms and mole crickets. Spittlebugs usually prefer centipede grass the most, but have been known to munch on the blades of St. Augustine grass as well. If you’re a Florida homeowner who’s noticed tiny black bugs in the grass, you are probably spotting chinch bugs. These insects will completely destroy a lawn, so taking action as soon as possible is necessary. Use the products located at the end of this blog for treatment or call a local lawn treatment company to come spray for them. Follow any product label instructions upon application.

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Pictured above from left to right: A chinch bug, fall armyworm and sod webworm.

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Pictured above from left to right: A billbug, grub worm and mole cricket.

If you are able to accurately identify and name the type of insect, grub or bug you are seeing, you can select an effective product for treatment and come up with a good prevention strategy in the future. Be sure to read the product labels thoroughly so that you know if the chemical can be applied to your lawn without damaging the grass. Follow the product label’s instructions upon application. It is important to know that there are a few cultural, non-chemical control methods for weed control you can use as well.

Cultural Methods of Insect Control in Your St. Augustine Grass

The first and most important tip for fighting off insects and pests in your St. Augustine lawn is keeping it healthy with regular maintenance practices. This includes mowing at the right times and at an appropriate height of 2–4 inches. Ideal mowing heights for St. Augustine slightly vary from brand to brand, but generally speaking, a height of 2–4 inches is optimal. Palmetto® St. Augustine is a semi-dwarf variety that performs best at a mowing height kept between 2–2.5 inches and CitraBlue® St. Augustine performs best at 2–3 inches.

Mowing reduces the amount of grass blade for insects to live and nest in. When grass becomes too tall in height, it provides optimal coverage for insects to reside in. They may even lay their eggs here and continue to feed. Keeping the surface of your lawn clean will reduce chances of insect infestation.

Don’t over irrigate your lawn. Most St. Augustine grass needs about one inch of water per week including rainfall. Not only does overwatering promote disease outbreaks; standing water is a perfect invitation for other pests like mosquitos, termites, cockroaches and other pests. Although these insects won’t severely damage your lawn, the standing water will weaken your lawn so that it can’t fight back against stressors like other harmful pests.

Pictured above: A size comparison of chinch bugs throughout their different growth stages with a ballpoint pen.

Another helpful tip is to dethatch your lawn. Thatch is a layer of debris below the grass that accumulates over time. It consists of all kinds of natural matter that eventually forms a semi-solid mat. Dethatch your lawn once a year or once every other year to keep the layer from becoming too thick.

Applying a fertilizer on your lawn may sound odd because it doesn’t directly reduce insect damage—but it does help your grass form a dense, thick layer above the surface of the soil so that insect damage doesn’t greatly impact the lawn. Apply fertilizer regularly to help your St. Augustine grass stay lush and healthy. Sod University recommends the Lawnifi® Fertilizer Program or Lawnifi Foundation.

Lastly, if you’re a homeowner that’s had a lot of problems with chinch bugs in the past, it may be useful for you to know that EMPIRE® Zoysia is a chinch bug resistant turfgrass variety. Learn more here.

Chemical Prevention for Insects in St. Augustine Grass Lawns

Oftentimes, the same type of insect control product for treatment of currently invading insects can be used for prevention, but at a smaller rate. It’s encouraged to apply a systemic insect control product at a preventive rate—especially if you’ve had problems with insect invasions in the past. Systemic insecticides are absorbed into the plant and circulate through the plant’s tissues. As a result, the chemicals kill the insects feeding on the plants.

Sometimes you can prepare ahead of time by purchasing an insect control product labeled to treat the kind of insect you’ve experienced in the past. On the other hand, if you aren’t sure which kind of insect you might see in the near future, a broad-spectrum insect control product may be your best option. A broad-spectrum insecticide, as its name suggests, will be labeled to control a wide range of common insects.

In either scenario, you will be applying less product for prevention than you will for fighting an invasion off—and less product means less money. This is why we believe it’s better to apply preventatively than it is to apply at a curative rate.

Be sure to read the product labels thoroughly so that you know if the chemical can be applied to your lawn without damaging the grass. Follow the product label’s instructions upon application.

Chemical Treatments for Insects in St. Augustine Grass Lawns

After you’ve accurately identified the kind of insect that is causing damage to your lawn, you can begin researching the best insecticide to kill off the insect you’re seeing. Our blog on The Best Insect Killers for Home Lawns suggests a list of some of the best ones available including a few options containing Bifenthrin and Imidacloprid. Here are a few of our top-recommended products.