How to Get Rid of Lawn Grubs Fast Before They Damage Your Yard

• Grubs are the larvae of scarab beetles, and can damage grasses and lawns by feeing on stems and leaves.
• Dry, patchy grass with no solution and animals digging in the grass are telltale signs of an infestation of grubs.
• There are various methods (like bacteria or insecticides) to control and eradicate grubs depending on where they are in their life cycle.

Grub control is a necessary part of lawn maintenance. These common pests are found all across the U.S. and can quickly become an infestation in areas with rainy seasons and moist soils.

Find out how to get rid of grubs, how many are too many, signs of infestation, and when and how to treat for best results.

What Are Lawn Grubs

Lawn grubs are larvae of scarab beetles. Different turf grasses and climates attract up to eight different species with Japanese and June beetle grubs most prevalent. They feed on grass roots and stems, and adult beetles strip and damage leaves on ornamentals and crops.

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8 Signs of Grubs in Your Lawn

Grubs are a good source of food for animal pests that tunnel through your lawn or dig holes that turn your green space into a minefield. Watch for these signs of infestation:

• Irregular patches of dead or dying grass that increase in size. Blades appear brown, thin and wilted.
• Turf feels spongy when walked on.
• Patches of grass peel back or pull up easily.
• Lawn appears dry even after watering.
• Numerous small holes from digging by skunks, raccoons, opossums, squirrels, or foxes.
• Tunneling and mounding caused by mole activity.
• Large populations of crows, grackles, and starlings appear on your lawn.
• Swarms of beetles close to the ground.

How to Get Rid of Lawn Grubs

Successfully controlling lawn grubs relies on timing and the growth phase of the insect; depending on these factors, treatment can be either preventive or curative. Life cycle stages vary according to climate.

Preventive Insecticides

Preventive chemicals imidacloprid, thiamethoxam or clothianidin applied early to midsummer target and destroy newly laid eggs reducing numbers for the following spring, but do not affect current year adults. Chlorantraniliprole is slightly less effective but can be applied as early as late spring and will not harm bees.

Mow prior to application to remove flowering weeds that attract foraging pollinators and avoid drift to flowerbeds and ornamentals. Use a fertilizer spreader for granular products. Other formulas are mixed with water for spraying.

Water all products in to a depth of half an inch.

Curative Insecticides

Carbaryl and Trichlorfon are the only insecticides that reduce the current season’s grub population, but lawns must be treated before they stop feeding to pupate in late spring. These short acting insecticides are less effective than preventive controls, but can be applied when grubs actively feed from early autumn until late spring. It may take several weeks to see results.

Mow before application to protect foraging pollinators. Distribute granular products evenly with a fertilizer spreader and water in to a depth of half an inch. Maintain the lawn with adequate water and fertilizer. Consider an application of preventive insecticide the following summer for continued control.

Milky Spore

Milky spore is a bacterial disease with long-term control for Japanese beetles. The active organism requires ten or more grubs per square foot to spread efficiently, and may take two to four years to achieve complete control of an infected lawn. The bacteria is dormant when applied and must be eaten by a warm larvae to activate and spread.

Spread milky spore powder in a grid pattern using a teaspoon every 4 feet in rows 4 feet apart. It can be distributed any time, but works best when larvae are immature. Milky spore won’t harm other insects and can remain in soil for up to fifteen years.

Beneficial Nematodes

Beneficial nematodes parasite on grubs by entering their body openings and multiplying rapidly. They can be tricky to use and become sterile if exposed to direct sunlight.

Beneficial nematodes come in sponges, gels, granules or liquid and work best applied on moist soil in the morning, evening or on an overcast day. They can be stored in the refrigerator for up to three weeks.

If ground is dry, water to a depth of half an inch before application. Applications work quickly with maximum results in three to four weeks, but extended dry periods may require a second dose.

Neem Oil

Neem oil is a botanical pesticide with insecticidal properties that interrupt feeding, growth, and egg laying. It’s most effective applied from late summer into early autumn. Follow product label instructions for mixing and spray affected areas.

Diatomaceous Earth

Using diatomaceous earth is an organic approach however this product kills all soft-bodied insects including butterfly and lady beetle larvae. It’s made up of silica and works by cutting into the larvae causing dehydration and death. Best used for spot treatment, it usually comes in powder form and should be applied according to label directions.