The Simple Guide To Diagnosing And Controlling A Grub Infestation

BY pure turf
May 9, 2023
Lawn Care

You aren’t alone if the thought of grubs in your yard gives you the creeps! After all, grubs aren’t exactly cute, and the thought of any pest infesting your space is disturbing. 

And besides that, they can cause a lot of damage to your yard, creating patchy brown spots and wrecking your dreams of a beautiful yard with lush, green grass. 

Do you have unsightly brown spots in your yard that make you want to run and hide every time you host a backyard picnic? 

Maybe you’ve tried watering, fertilizer, or aerating, but the patches refuse to diminish. 

If that’s the case, you could be dealing with an infestation of white grubs in your yard! 

The good news is that you aren’t stuck if you are dealing with grubs. Today Pure Turf would like to tell you how to figure out if you have a grub problem, how to deal with grubs, and many more lawn tips to help you create the lush, green lawn you dream of.  

Ready to learn how you can eliminate your grub problem? 

Let’s get started!

Why Are Grubs A Problem? 

Lawn grubs, sometimes called white grubs, are the larvae of beetles such as June Beetles, Japanese Beetles, Masked Chafer Beetles, and others. The beetles lay their eggs in the ground, the eggs hatch into grubs, and the grubs mature into beetles. 

Most lawns have a few grubs, and as long as it’s just a few, they aren’t an issue. However, if too many grubs infest your yard, they cause major damage. 

Here’s why they are a problem: 

  • Grubs feed on grassroots and other organic matter. If there are too many, they can decimate the root system in your lawn and kill the grass, causing unsightly brown patches and unhealthy sod. 
  • Grubs attract other pests, such as moles and raccoons. These critters love eating grubs! Moles tunnel all over your yard in search of grubs, and coons and other top-dwellers dig down to find them. 
  • If you leave a grub problem untreated, it increases exponentially. The grubs mature into beetles that hatch and feed on your grass, and as they feed, they release chemicals that communicate to other beetles that your lawn is a tasty feast, and all the beetles in the vicinity join the party. Then you’ll have even more grubs–each beetle can lay up to 60 eggs!  

Don’t think you are doing something wrong if you have a grub infestation–actually, the beetles are attracted to healthy lawns because they are a consistent food source, so if you have grubs you are probably doing something right. But if your grub problem persists, your lawn will not stay healthy. 

4 Signs Of Grub Infestation 

You can see that grub infestation is an issue! But how do you tell if you have a grub problem? 

Here are a few signs of grub infestation

  1. The most common sign is patches of brown or yellow grass in your yard. These patches look similar to a drought-stricken yard, only they grow despite watering. Brown patches normally show up only when the grub damage is extensive and are often a sign of grub damage from the previous year. 
  2. Turf that gives slightly when you walk on it or feels spongy is often a sign that grubs have damaged the grassroots and the turf is becoming porous. If the infestation gets really bad, you can roll your turf up like a carpet. 
  3. A grub infestation is a smorgasbord for anything that eats grubs, so if you see birds, coons, moles, or other critters digging in your yard, that may be a sign of a grub problem.  
  4. Excess amounts of beetles loitering around your lawn or zooming low over the ground's surface is another tell-tale of grub infestation. You can also check for beetle damage on plants and shrubs near your yard. 

To find out if you have a grub infestation, test your lawn by digging up one square foot of lawn and counting the grubs in it. Test several different spots if you have a large yard. A few grubs aren’t harmful, but if there are ten or more grubs per square foot section, you have an infestation. 

Grub infestations do not go away on their own, and if they go unnoticed they get worse, so it’s imperative to deal with them as soon as possible! 

How To Control Grubs In Your Yard 

Understanding the grub life cycle 

Before talking about grub control methods, it’s essential to understand the grub life cycle. For most species of beetles, the life cycle lasts a year and consists of four stages: egg, larvae, pupa, and adult. 

Here’s how it looks, step-by-step:

  1. Adult beetles lay their eggs in the ground in the early summer months, normally between June and August. 
  2. The eggs hatch within two weeks, and the tiny larvae begin eating grass roots.
  3. The grubs eat and grow until it gets cold, then they burrow deep into the ground below the freeze line and remain dormant until it warms up in the Spring. 
  4. The grubs wake up and finish eating and growing in the Spring, then become pupae and morph into adult beetles. 
  5. The adult beetles hatch in early summer and spend several weeks mating and laying eggs, which hatch in two weeks and restart the cycle. 

The best time to treat for grubs is normally in late summer when the eggs have hatched and the larvae are still small and vulnerable. However, ideal timing varies for different grub control methods. 

5 Methods for controlling grubs 

There are various methods for controlling grubs. Here are a few of them. 

1 - Attract birds or get some backyard chickens 

A grub-infested yard is a chicken buffet! Chickens may not completely take care of a severe grub infestation, but they can help keep the numbers down. Plus, the grubs are a free source of chicken feed! 

Of course, chickens are only an effective solution if you want them in your yard. Some people may not like the idea of chickens in their backyard much more than the idea of grubs! 

Backyard birds such as bluejays also love eating grubs, so if you can attract grub-eating birds to your property with bird baths, feeders, and bird houses they can also help keep grub populations in check. 

2 - Apply nematodes 

Nematodes are tiny, parasitic roundworms that invade grubs’ bodies and reproduce inside, releasing chemicals that kill the grub.  

You can buy nematodes online and apply them to your yard to control the grub population. How long it takes to get rid of grubs using nematodes depends on the scale of the grub infestation, but it may take up to three years to destroy a large colony. 

One upside of applying nematodes to your yard is that it’s all natural, and you don’t have to use harsh chemicals. 

3 - Use milky spore 

Milky spore is a bacteria that is fatal to Japanese Beetle grubs. By applying it to your yard, you can control the grub population. However, it only works for Japanese Beetle control, not every species of white grub.  

You can buy milky spore online. For milky spore to be effective the grubs have to eat it, so the best time to apply it is early Fall when the grubs are the most active and hungry. 

Like nematodes, using milky spore to control the grub infestation may take some time, but it’s an effective and all-natural Japanese Beetle grub control method. 

4 - Use an insecticide 

If all else fails, there are chemical treatments for controlling grubs. You can buy pesticides containing chemicals such as chlorantraniliprole, carbaryl, and trichlorfon, and some people even swear by homemade solutions of Borax. 

You should use chemicals such as these with caution as they are toxic and may harm your lawn, pets, or family if improperly used. 

5 - Other preventative measures

If you suspect that grubs might be quietly congregating below the surface of your lawn, there are a few simple, practical ways you can deter them. 

Here’s how you can make your yard a less inviting place for grubs: 

  • Dethatch and aerate your lawn. Thatch provides a dense layer of shelter for beetle eggs and grubs. Removing it and aerating the lawn makes it less inviting. It also allows solutions such as milky spore, nematodes, and insecticides to penetrate the lawn more easily, making them more effective. 
  • Limit moisture in your yard. Grubs love moisture! You need enough moisture for your grass to survive, but if there’s a dry spell, consider skipping the water for a week or two and letting your lawn get good and dry. This deters grubs, and the grass normally perks up quickly once you start watering again. 

Also, limiting the moisture in your yard helps deter other pests such as mosquitos! 

  • Introduce natural predators. As we mentioned before, birds and chickens love eating grubs! Making your backyard a haven for birds can help keep grubs in check. 

Of course, you always have the option of hiring a lawn care pro! A pro lawn care service can help you easily eradicate your grub problems and leave your lawn looking fantastic, all while you relax on the porch with a glass of iced tea. 


We hope this article helps you deal effectively with any grub issues in your yard! 

If you find grubs too gross to deal with or don’t have the time to handle your lawn issues yourself, call us here at Pure Turf! 

Pure Turf offers professional lawn care services in the Nashville area, TN. We offer grub control and other lawn services, including: 

  • Lawn fertilization & weed control
  • Aeration & seeding
  • Lawn disease & prevention
  • Soil health elite
  • Mosquito control 

Give us a call today to learn more, or get a free estimate for one of our lawn care plans, Standard, Premium, or Elite! We look forward to hearing from you. 

Always up-to-date.
Sign up to our newsletter.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
Sign up to receive our Free Lawn Care Guide and to stay in the loop with new service offerings and updates!