Grub Season: When Do Those Pesky Pests Emerge?

June 20, 2024
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Have you noticed brown patches in your lawn that won’t bounce back? Are pesky birds and animals digging up your yard? If so, you might be facing an unwelcome visitor: the grub. These fat, C-shaped larvae of various beetles can wreak havoc on your lawn’s health. But when exactly is grub season, and how can you identify and deal with these destructive creatures?

Whether you’re a seasoned gardener or just starting lawn care, understanding when grub season hits and how to manage it effectively is important for maintaining a healthy outdoor space. This article explores when these pesky critters emerge and provide actionable tips for keeping them at bay.

When is Grub Season?

Grub season typically corresponds with the warm months of late spring and early summer. In temperate climates, grub activity peaks typically between May and August. However, the exact timing can vary depending on geographic location, weather patterns and temperature.

Grubs are most active during two periods:

Early Spring (April-June): Newly hatched grubs feed on your lawn’s root system.

Late Summer/Early Fall (August-October): Mature grubs continue to feast on roots, causing the most significant damage to your lawn.

When Do Grub Worms Come Out?

Grubs are only sometimes present on your lawn. Their lifecycle determines their activity periods. The timing of their emergence is influenced by various environmental cues, including soil temperature and moisture levels. Generally, grubs become more active when soil temperatures reach 60°F (15°C) or higher.

Egg Laying: Adult beetles lay eggs in the soil during the late summer or early fall (typically August to October). These eggs remain dormant through the winter.

Hatching: The eggs hatch into grubs in spring (around April to June). These young grubs feed on grassroots throughout the summer and early fall.

Maturity: As fall approaches, grubs mature and burrow deeper into the soil to pupate.

Emergence: The following spring or summer, adult beetles emerge from the pupae and complete the cycle by laying a new generation of eggs.

Identifying Grub Damage

While grubs themselves might be hidden underground, there are telltale signs that can help you identify an infestation:

Brown Patches: Grubs munch on grassroots, leaving brown, patchy areas in your lawn that struggle to recover, even with watering.

Spongy Lawn: Grub activity loosens the soil, making it feel spongy underfoot.

Animal Activity: Raccoons, skunks, moles, and birds love to feast on grubs. If you see increased animal digging in your yard, it might be a sign of a grub infestation.

Here’s a tip: If you suspect grubs, perform a simple test. Dig up a small section of your lawn (about one square foot) and remove a two-inch section of sod. If you find more than 5-10 grubs per 1.000 square foot, you likely have an infestation that requires treatment. Remember to dig in areas with green grass on the edge of the brown or yellow patches. These discolored areas have already been eaten and the grubs will most likely have moved into greener grass areas. You can also search for lawn grub control in OKC to have a professional inspect your lawn.

Preventative Measures and Treatment Options



The best defense against grubs is a good offense – prevention. Here’s how to keep your lawn grub-free:

Maintain Healthy Soil: Healthy soil promotes strong grassroots, making it more resistant to grub damage. Regular aeration, proper watering, and fertilization can improve soil health and reduce the likelihood of infestation.

Practice Proper Lawn Care: Mowing grass to the appropriate height and frequency can help deter adult beetles from laying eggs in the soil. Additionally, avoiding overwatering and excessive thatch buildup can create less hospitable conditions for grubs.

Use Beneficial Nematodes: Beneficial nematodes are microscopic organisms that prey on grubs and other soil-dwelling pests. Introducing nematodes to your lawn can help control grub populations naturally without harming beneficial insects or plants.

If you already have a grub problem, here are your treatment options:

Biological Control: Bacillus thuringiensis (Bt) is a naturally occurring soil bacterium that produces toxins lethal to certain insect larvae, including grubs. Applying Bt-based products to the soil can effectively target grubs while minimizing harm to non-target organisms.

Chemical Control: In severe cases of grub infestation, chemical insecticides may be necessary to achieve control. However, it’s important to exercise caution when using these products and follow label instructions carefully to minimize environmental impact.

Keeping Your Lawn Grub-Free: A Year-Round Effort

Understanding grub season and taking proactive measures can keep these destructive pests at bay. Remember:

Spring (April-June): Apply preventative treatments to target newly hatched grubs.

Summer (July-August): Monitor your lawn for signs of grub damage.

Fall (September-October): Consider curative treatments if necessary, as this is when mature grubs cause the most damage.

Grub season presents a significant challenge for homeowners and landscapers alike, but with proper knowledge and proactive management strategies, it’s possible to mitigate the damage caused by these persistent pests.

Don’t wait for brown patches and spongy soil to take over – contact Don’s Lawn today for the best lawn care in OKC! Our experienced professionals can assess your lawn for grub activity and recommend the most effective treatment plan, ensuring your grass stays lush and vibrant year-round.


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