How to Get Rid of White Grubs in Soil

A thick, green lawn doesn’t happen by accident, and in Kansas, it takes vigilant care to keep it that way. One of the most destructive threats lurking beneath your grass is white grubs. These C-shaped larvae feed on grass roots below the surface, slowly starving your lawn of water and nutrients. As they grow, their feeding can cause patchy, brown spots that won’t improve, no matter how much you water or fertilize. If you’re noticing irregular damage or soft, spongy turf, it’s time to dig deeper. Our lawn care experts have put together everything you need to know to identify, confirm, and effectively control grub infestations before they devastate your yard. 

What Are White Grubs? 

White grubs, the C-shaped larvae of several beetle species commonly found in Kansas lawns, such as Japanese beetles and June bugs, are among the most destructive lawn pests in the region. After adult beetles lay eggs in mid-summer, the newly hatched grubs begin feeding on grass roots just below the surface within weeks. The most significant damage occurs from late summer into early fall, when the larvae reach their largest size and aggressively consume roots, causing widespread turf thinning, browning, and potential lawn destruction from the ground up. Early identification and proper grub control are essential to protect your lawn. 

Signs of White Grub Damage in Kansas Lawns 

Knowing what to look for can help you catch a grub problem before it devastates your lawn. Keep an eye out for these early warning signs that suggest grubs might be at work beneath your turf:

• Irregular Brown Patches: You might see patches of grass that turn brown or yellow, especially during late summer or early fall. These areas often start small and expand quickly. Unlike drought stress, these spots might not improve even with watering.
• Spongy or Loose Turf: Your lawn might feel spongy or soft underfoot, almost like a loose carpet. In severe cases, you can roll back sections of turf because the grubs have eaten through the roots holding the grass to the soil.
• Increased Animal Activity: A sudden increase in animals digging in your lawn can be a major red flag. Birds, skunks, raccoons, and even moles love to feast on grubs, and their foraging can cause additional damage to your yard.
• Wilting Grass (Even When Watered): Grubs destroy grass roots, making it difficult for your lawn to absorb water and nutrients. You might notice areas of grass that wilt or yellow even if they're receiving adequate moisture.

While a few grubs are normal and won't harm your lawn, finding a population of 8 to 12 grubs per square foot indicates a serious infestation that can lead to significant root damage and attract nuisance wildlife.

How to Find Grubs in your Kansas Lawn 

If you suspect grubs based on the signs above, a quick test can confirm their presence and help you assess the severity of the problem.

To quickly confirm a grub infestation:

• Choose a Spot: Select an area of your lawn that shows signs of damage or where you suspect grubs are active.
• Peel Back the Turf: Using a spade or shovel, carefully cut and peel back a 1-foot by 1-foot section of turf. Aim to cut about 2 to 4 inches deep to get into the root zone.
• Inspect the Roots and Soil: Gently examine the exposed soil and the underside of the lifted turf. Look for C-shaped, creamy white grubs, typically ranging from ½ to 1 inch long. They'll often be curled up.
• Count and Act: Count the number of grubs you find in that square foot. If you discover 8-10 or more grubs, it's a strong indicator that treatment is necessary to prevent significant lawn damage.

Are White Grubs Harmful? 

Yes, white grubs can be very harmful to your lawn. These C-shaped larvae feed on grass roots beneath the soil surface, which disrupts the lawn’s ability to absorb water and nutrients. As the grubs grow larger, their feeding becomes more aggressive, leading to thinning turf, brown patches, and eventually widespread lawn damage. Severe infestations can destroy your lawn from the roots up, making it crucial to identify and manage grub populations early.

However, white grubs are not harmful to people. They do not bite, sting, or transmit any diseases. Their impact is limited solely to damaging grass and turf, so while they can ruin your lawn, they pose no direct threat to human health or safety.

Why Do I Suddenly Have Grubs? 

Grubs appear suddenly because of the lifecycle of the adult beetles that lay eggs in mid-summer. After laying eggs in your lawn, the larvae hatch within a few weeks and begin feeding on the grass roots. This feeding damage often becomes noticeable from late summer through early fall when the grubs are largest and most voracious. Changes in weather, natural beetle population cycles, or nearby untreated areas can cause a sudden increase in grub activity and damage to your lawn.

Grub Control in Kansas: When and How 

Tackling grubs effectively depends on applying the right treatment at the right time. Your approach will differ based on whether you're preventing future damage or dealing with an active infestation. 

Timing Your Grub Treatment 

The key to successful grub control often lies in applying treatments at the right time. Your approach will depend on whether you're aiming for prevention or tackling an existing problem:

• Preventative Treatment:
  • When: Apply in late spring through early summer (typically May to mid-July in Kansas), when newly hatched grubs are small and most susceptible to insecticides.
  • How: Use products containing active ingredients like imidacloprid or chlorantraniliprole. These are designed to disrupt the grubs' life cycle before they can cause significant damage. Apply before mid-July for optimal effectiveness.
• Curative Treatment:
  • When: Most effective in late summer to early fall (August to October), as soon as grub damage becomes visible (e.g., browning patches, spongy turf).
  • How: Utilize fast-acting insecticides such as carbaryl or trichlorfon. These products are designed to quickly reduce active, larger grub populations. Prompt application is crucial once damage is identified.

Optimizing Your Grub Control Efforts 

For best results with any grub treatment and to maintain a resilient lawn:

• Water Thoroughly Post-Application: Always water your lawn immediately after applying grub control products. This helps the active ingredients penetrate the soil and reach the root zone where grubs feed.
• Avoid Overwatering: While watering is essential, excessive moisture can create an ideal environment for adult beetles to lay eggs, potentially leading to future infestations. Water deeply but infrequently.
• Promote Lawn Health: A strong, healthy lawn is naturally more resistant to pest damage. Maintain regular mowing, proper irrigation, and consistent fertilization practices to enhance turf vigor and reduce susceptibility to grubs.

Looking for a more natural approach to grub control? We’ve got you covered—read the full guide here. 

Quality All Care Lawn Services: Your Partner in Grub Prevention and Control 

When it comes to protecting your Kansas lawn from destructive grubs, expert help makes all the difference. Quality All Care Lawn Services offers proven grub control solutions tailored to your lawn’s unique needs. With years of experience helping Kansas homeowners, our team delivers safe, effective lawn pest control treatments that stop grubs before they cause lasting damage—keeping your lawn healthy, green, and vibrant all season long. Don’t wait for grub problems to worsen; contact Quality All Care Lawn Services today and get a customized lawn care plan to get rid of grubs and get your lawn healthy and thriving.