Grub Worm Treatment: How to Protect Your Lawn from Lawn-Eating Pests

Grub worms — also known as white grubs, lawn grubs or white grub worms — are the larval stage of several common beetle species, including:

• Japanese beetles
• June beetles (June bugs)
• European chafers
• Masked chafers

While adult beetles are visible above ground, the most damaging phase of their life cycle occurs below the soil surface.

Adult beetles lay eggs in lawns during warmer months, often favoring areas with moist soil and healthy turf. Once eggs hatch, young grubs move into the upper layer of soil and begin feeding on grass roots. Because roots are responsible for absorbing water and nutrients, this feeding directly weakens the lawn.

As grub feeding continues, lawns may experience:

• Thinning grass that struggles to stay green
• Increased stress during heat or drought
• Brown or dead patches that expand over time

In severe cases, large sections of turf can die completely, and damaged grass often lifts easily from the soil surface because the root system has been destroyed. After feeding, grubs pupate, or transform, the following spring and later emerge as adult beetles, restarting the cycle.  

Timing plays a major role in whether grub worm treatment is effective. Grubs move through several life stages (eggs, larvae, pupae and adult beetles), and treatments are not equally effective at every point in that cycle.

Preventive grub control focuses on stopping damage before it begins, when eggs hatch and young grubs are developing close to the soil surface. At this stage, grubs are smaller and easier to control.

Key timing considerations include:

• Preventive treatments are typically applied in late spring or early summer
• Curative treatments target active larvae later in the season
• Larger, mature grubs are more difficult to control

Soil conditions also influence results. Adequate moisture helps insect control products move into the root zone where grubs feed, while extremely dry or compacted soil can reduce effectiveness. Matching the right treatment to the right moment in the grub life cycle is essential for successful grub control.

Not all grub worm treatment options work the same way. Choosing the right approach depends on whether grubs are already feeding or if treatment is being applied preventively.

Curative treatments are designed to reduce active grub populations and may include:

• Insect control products or insecticides that target larvae
• Applications timed to peak grub activity
• Treatments focused on grubs feeding on grass roots

Some homeowners explore natural options such as beneficial nematodes, milky spore or neem oil. These methods can help control grubs under certain conditions, but results vary based on soil temperature, moisture and grub species.

Preventive treatments focus on stopping damage before it begins and typically involve:

• Early-season applications
• Interrupting the grub life cycle before feeding starts

DIY grub control products may help in some situations, but professional pest control services from TruGreen provide expert response, accurate timing and product selection tailored to lawn conditions.  

Once grubs are controlled, lawns need time and support to recover. Repairing grub damage doesn’t happen overnight, especially if the grass roots were severely affected. The goal during recovery is to help turf reestablish strong roots while minimizing additional stress on the soil.

Recovery efforts may include:

• Overseeding thin or bare areas to restore coverage and density
• Fertilization to encourage root regrowth and support new grass development
• Proper watering to help seed and existing turf establish without oversaturating the soil

Even with the right approach, certain mistakes can slow recovery or limit results, including:

• Treating too late in the season, when turf has limited time to regrow
• Using the wrong grub control product for the stage of infestation
• Overwatering damaged turf, which can weaken roots and thin out existing grass

Supporting long-term lawn health also plays an important role in preventing future infestations. Practices such as mowing at the proper height, maintaining balanced soil nutrition and supporting beneficial organisms in the soil can help lawns better tolerate pest pressure. Over time, a dense, healthy lawn is less inviting to pests and better equipped to recover if damage does occur.