11 Ways to Get Rid of Lawn Grubs Naturally!

What Are Lawn Grubs?

Grub dug up from lawn soil — *Grubs are the white larvae of various scarab beetles.*

Beetles go through a complete metamorphosis – egg, larvae, pupa, adult. Most beetle larvae are mild-mannered and don’t bother anybody. However, the larvae form of the scarab beetles eat grass roots as they grow up, often in high enough numbers to destroy a lawn.

Included in this guilty group are the larvae of the May and June beetle, the Japanese beetle, as well as the garden chafer, the rose chafer, and rhinoceros beetle. These are collectively called white grubs or engerling in some places.

We’ll be focusing on the grubs that damage lawns and how to control them and protect your grasses!

Jump to:

Damage Caused by Grubs
11 Natural Methods to Control Grubs
Let Grass Grow Long
Water Less
Plant Grasses with Deep Roots
Tilling and Hand-Picking
Beneficial Bacteria and Nematodes
What Are Beneficial Nematodes?
What is Milky Spore Disease?
What is Bacillus thuringiensis var. galleriae?
Bring Helpful Birds and Insects into the Yard
Encourage Bird Activity
Encourage Beneficial Insects in the Yard as Well
Spikes o’ Death

Damage Caused by Grubs

Lawn damage caused by a grub infestation — *Chafer grubs are responsible for this kind of damage. The grubs feed on the grass roots until the grass is no longer able to attach to the soil. Animals and birds also dig up the turf to get at them.*

Yellow or dead patches of grass in the lawn.

The turf feels spongy. There might even be places where you can roll back the grass – and you’ll see the small white grubs in the soil underneath.

A sudden increase in beetles.

If you notice the dead patches of grass, then see tan June beetles bonking against your outdoor light at night – or Japanese beetles attacking your roses – then it’s possible you have a grub problem.

Increased bird, skunk, or mole activity.

Grubs are a great food source for other creatures. Birds will pick the grubs out of your grass. But other animals, like skunks, moles, and raccoons, will dig for the juicy treats, further wrecking your lawn.

How to confirm grub presence.

Lift up a section of your grass to check for grubs. If you have the above problems, and see a number of grubs busy around your grass roots, it’s time to check out some control methods!

11 Natural Methods to Control Grubs

Natural control methods are best. Here are 11 ways to control grubs in your lawn.

Let Grass Grow Long

Grass growing lawn to thwart bettles — *An English back garden where the grass grows long. It’s better for the environment and it frustrates beetles in their egg laying – two definite wins.*

Japanese beetles prefer to lay eggs in short grass. They’ll flock to close-cut lawns and are less likely to lay eggs in grass that’s more than 2 inches high. During summer, while beetles are busy mating and laying eggs, raise the mower deck up to its highest setting. Let the grass get a little taller between mowings as well. This benefits your lawn by discouraging additional generations of white grubs. Longer grass doesn’t dry out as quickly, and it can protect roots from the hot, drying sun for better lawn health.

Tall grass also is more likely to harbor spiders and ants that like to snack on beetle eggs.

Read more about Japanese beetles here!

Water Less

The longer lawn will also help with this tip: water less. When the beetles die off in late summer and early fall, the young grubs are growing underground.

Help grubs get off to a bad start by watering the lawn less than usual.

Plant Grasses with Deep Roots

Grub resistant grass — *Tall fescue is a bunch type grass that spreads and has deep roots that grubs can’t access.*

Shallow-rooted grasses like creeping bentgrass look really cool, but if lawn grubs are a problem, the bentgrass is going to be coming up in rootless sheets with grubs chomping the roots to nubbins.

Deep-rooted grasses like turf type tall fescue are less susceptible to grubs because their roots delve into the soil, well past the top layer where grubs hang out. The deep roots also make them drought tolerant and more disease resistant than other grasses.

Really, converting your grass to native fescues is good for the yard, since native plants are more pest and insect resistant. If you’re fine with growing a more lackadaisical yard, mix white clover in with your grasses. The clover roots will add nitrogen to the soil while attracting pollinating insects, and it grows happily through the year and the grubs have no effect on them.

Learn more:

Tilling and Hand-Picking

Grubs in compost — *Rose chafer larvae in compost.*

As with other pest insects, hand-picking is also possible for grubs in areas of severe damage where the turf has come loose. The turf can be lifted and shaken out, and grubs will fall from the grass. If the turf is dead, pick it up, grubs and all, and put it into a plastic bag or a bucket.

Run a hard rake over the bare soil to till the soil and expose grubs. Pick them out and drop them in a bucket. Once you reach the edges of the bare soil, lift the grass 6 inches out from the infested area, and remove grubs from here. This is necessary because grubs will keep moving outward, looking for healthy roots to feed on.

It might seem surprising, but the smallest grubs will cause the most trouble for your yard. These will be staying in the soil through fall, winter, and spring, munching on grass roots and plumping up. The large grubs won’t be causing much trouble – they’re likely ready to metamorphose into adult beetles. They will be leaving the trouble in the ground to create new trouble in your leaves and flowers.

When the grubs are gone, spray the rest of the lawn with one of the organic methods in this article. Seed the area with a deep-rooted grass variety, or use a few rolls of sod to cover the area and make it look good.

The bucket o’ grubs can be disposed of in soapy water. Or, put them in a container near your birdfeeders mixed with grains to bring the birds to the yard. (Use a plastic container that the grubs can’t climb out of.) The birds will love you for it, and they might even pick through the garden soil for grubs you’ve missed.

Beneficial Bacteria and Nematodes

Large glove held in a gloved hand — *A Grub Of Unusual Size, or a G.O.U.S.*

The microscopic creatures in this section target and kill grubs in the soil.

Read about how to spray organic pesticides safely.

What Are Beneficial Nematodes?

Nematodes are tiny, sometimes microscopic, creatures that look like tiny white worms or a white piece of hair. Some nematodes are harmful like root-knot nematodes that destroy tomato roots.

These specific nematode species are beneficial because they target grubs.

How they work: These nematodes have a partnership with a certain kind of bacteria. The nematodes ingest the bacteria when they find a grub, and then they crawl inside the grub through its mouth or spiracles. Once inside, the grub turns the bacteria loose, and it multiplies and kills the grub, then makes the grub unpalatable to other fungi and bacteria that want a taste. But to the nematode, the grub is a banquet of delight and commences to eating and multiplying. After a time, other nematodes, with their bacteria partners, sally forth into the world to target other grubs for tasty sustenance.

The nematode species that are often sold for the task is Heterorhabditis bacteriophora (Hb), which targets grubs of Japanese beetles, chafers, and other beetle larvae but leaves most other insects alone.

Note: These are kept in the fridge and are sold on a sponge, in gels, granules, or liquid form. Keep out of the sun, applying at dusk, in cloudy conditions, or during light rainfall.

Application

Use nematode sprays during spring or fall when grubs are active.
Before buying, check the expiration date. The beneficial nematodes or bacteria have got to be fresh. Expired containers means that you’re buying mostly dead organisms which will not do any good in the yard.
Water the yard before applying. They need moist soil to survive.
Apply them during cloudy days or after the sun sets. Sunlight kills the nematodes.
Apply when temperatures are within a comfortable range (often listed in the directions).

What is Milky Spore Disease?

*An Asian rhinoceros beetle larva, an insect pest that attacks coconuts and other plants.*

Milky spore disease (Paenibacillus papillae, formerly known as Bacillus papillae) is a bacterium that specifically targets Japanese beetles, so it’s safe for humans, animals, and other insects. however

However, milky spore is not meant for instant control. It must be used over several years in order to build up a population of long-term biological control in the soil. Once it’s established, it can remain in the soil for 10 to 30 years.

When eaten by the Japanese beetle grub, this bacteria reproduces and turns the grub a milky white color. The grub dies, and the bacterial spores disperse into the soil.

Apply in the hot days of late summer when the soil temperature is above 65 degrees. It works better in hot temperatures and works best when there are lots of grubs in the soil to spread the disease. In cooler areas, such as the Northeast United States, it can take longer for the disease to spread in the soil.

Learn more:

What is Bacillus thuringiensis var. galleriae?

Also known as GrubGONE, this is a new B. thuringiensis variety that targets a wider array of soil grubs in the scarab family, but without affecting pollinator species or beneficial insects. It targets not only Japanese beetles, but other related beetles like May and June beetles, a variety of chafers, and even the annual bluegrass weevil in some places.

Like the milky spore disease, it’s not meant as an instant control but as a useful beneficial soil organism whose population needs to be built up over time for best results. However, it’s as effective as regular turf insecticides, and stays in the soil after application, its effect growing over time.

Apply in springtime when grubs come up from deep in the soil to get busy feeding on grass roots. Apply again in late summer when newly hatched grubs are in their first weeks of development.

This comes in granular form that can be dispersed with a walk-behind spreader. It’s also available in a form for grown beetles called BeetleGONE!

Application Tips for Beneficial Nematodes and Bacteria

Because you’re buying living beings, the key is to keep them alive while putting enough of them out there into your lawn so some of them will make it to the grubs – and there have to be enough grubs in the lawn to make this expenditure worthwhile.
Buy beneficial creatures/diseases only when there are enough grubs in the yard to be a real problem. Almost every lawn will have a few grubs, and that’s fine. It does more damage to kill every grub on sight.

Bring Helpful Birds and Insects into the Yard

Encourage Bird Activity

Robin eating a beetle — Birds such as robins, grackles, and other insect-eaters are helpful when it comes to picking grubs and other insect pests out of the lawn.

Birds are extremely helpful predators of grubs. Some birds prefer seeds, but some birds – including wrens, grackles, robins, starlings, and blackbirds – eat insects, including lawn grubs. If you’re attracting birds to the yard, never use systemic insecticides to kill grubs. Many chemical grub-killers are systemic, which means the grub absorbs the poison. Birds pluck the poisoned grubs from the ground and eat them or gather a beakful and feed them to their chicks, and then those birds die as well.

This happened in Australia in 1991. Workers sprayed the lawn around the new Parliament House for grubs, and a number of magpies were killed by it.

If you’re plagued by heavy infestations of grubs, however, sometimes you need to spray. Use only chemicals registered specifically for grubs, and spray the lowest dose possible, just before a rain. Always follow label instructions.

The lowest minimum dose will do the trick and keep birds and other animals from dying.

Put up birdhouses for wrens and bluebirds. Put out food and water for birds. Have thick evergreen trees for songbirds to hide in and be safe.

Encourage Beneficial Insects in the Yard as Well

Spiders and ants eat beetle eggs. Insects such as wheel bugs, ground beetles, spined soldier bugs, and tachinid fly larvae snack on grubs. To bring beneficial insects to the yard, stop spraying pesticides that kill them. Plant flowers around the yard, especially nectar-rich flowers such as sweet alyssum, coneflower, sedum, and Russian sage. Create wildish spaces in the garden where beneficial insects can live, lay eggs, and raise new pest-killing generations.

Spikes o’ Death

Aerating a lawn with shoe spikes — *Lawn aerating sandals don’t actually aerate the lawn, but they’re great for killing grubs.*

These were the brainchild of Dr. Whitney Cranshaw, professor of entomology at Colorado State University. Back in the day, diazinon was the main chemical used against chafer grubs. Cranshaw spotted a pair of “lawn aerator sandals” in a seed catalog, a pair of sandals with 3-inch-long spikes used to “aerate lawns” (they actually don’t).

He set up an experiment in which a grub-ridden lawn was sprayed with diazinon while he walked around an equally grub-ridden lawn in the “spikes o’ death.” When the turf was pulled up and the numbers of live and dead grub tallied, the spikes o’ death were just as effective as the diazinon.

Use the spikes o’ death in late spring, when the grubs are near the soil’s surface. Do not wear them in the house!! Wear work boots or sturdy sneakers, along with jeans, and push the spikes into the soil to strap them on. Then semi-march or penguin walk around the yard and don’t nick your legs with the nails. You will get a workout! If the straps come off, use duct tape to stick them on.

Caveat emptor: There are a lot of poorly-made lawn aerator sandals on Amazon where the spikes bend, the straps don’t work, the entire shoe breaks off, and they can’t be repaired. Be sure to check reviews.

Read more gardening advice from Rosefiend Cordell.