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Writer's pictureGerhart's Landscaping

When and How to Protect Your Grass from Pesky Lawn Grubs

Every homeowner wants to have a well-maintained green lawn, but this can easily turn into a nightmare if infested by lawn grubs. These little white worms inhabit the soil and feed on the grassroots, making your lawn unhealthy and vulnerable. 


Here’s how to recognize lawn grubs and how to eliminate them before they devastate your lawn.


What are lawn grubs?

Lawn grubs are larvae of certain beetles and chafers. Most of them stay in burrows, feeding on grass roots throughout most of their existence. Grubs exist in the soil for one to three years for some species before then transforming into adult beetles.


How to know when you have a lawn grub infestation

Here are some things to look out for:

  • Brown, patchy grass – Grubs feed on the roots of your lawn, so if portions of your lawn are brown and appear to be dead, the grubs might be the reason why the grass cannot absorb enough water and nutrients.

  • Spongy lawn – Does your lawn feel soft or bouncy any time someone steps on it? This might be because the soil feels loose, either because grubs have damaged the roots or because there is inadequate root mass.

  • Animals digging in your yard: If you find animals like raccoons and skunks burrowing around your compound more often, then it could mean an invasion.


How to check for lawn grubs

If you are a little uncertain that the grubs are the cause of your lawn problems, then there is a test you can perform. Follow these steps:

  • Pick a spot – Go to an area where the symptoms are, whether they are brown patches or soft grass.

  • Dig a square – Start by laying a shovel horizontally to dig a square-shaped chunk out of your lawn about one foot wide and 3 inches deep.

  • Look for grubs – Divide the soil and try to identify the number of grubs available in that particular soil. Experts say if you count over five within one square foot, then it is time for the lawn to be treated.


When is the best time to eliminate lawn grubs?

The timing of treatment differs depending on the type of grub and your location. However, it’s best to do it in early spring or during fall, as this is when the grubs are easily accessible at or just below the root zone to be affected by your soil treatment application. 

Always consult a local lawn care expert to know the right time to carry on with the process in your region.


Treatment options

Once it has been established that grubs are the cause of your lawn’s woes, it becomes time to get more serious. Here are some common ways to get rid of them:


Preventive treatments

These are best applied before grubs hatch, usually in late spring or early summer.

  • Nematodes – These microscopic worms are a natural option to prevent grubs. They seek out and parasitize grub larvae, reducing their population. Nematodes are safe for pets, plants, and humans.

  • Milky spore – Milky spore is a bacterium that targets specific grub species like Japanese beetle larvae. Once ingested, the bacteria multiply inside the grubs, killing them. The spore remains in the soil, providing long-term control.

  • Insect Growth Regulators (IGRs): Products like chlorantraniliprole inhibit the development of grubs. These chemicals stop grubs from maturing into beetles, providing long-lasting prevention when applied during the early stages.


Curative treatments

These should be applied once you have identified an active grub infestation, typically in late summer or fall.

  • Dylox (Trichlorfon) – Dylox is a fast-acting chemical that kills grubs within days. It’s effective as a curative treatment when grubs are actively feeding. This option is ideal for immediate relief but may require reapplication in severe cases.

  • Carbaryl – Another chemical treatment, carbaryl (sold as Sevin), works by killing grubs quickly. Apply it when grub damage is noticed for best results, ensuring the chemical penetrates the soil with thorough watering.

  • Organic neem oil – Neem oil acts as a natural pesticide, disrupting the feeding and growth of lawn grubs. It’s less toxic than chemical options but requires repeated applications for sustained effectiveness.

  • Aeration and topdressing with organic matter –  This not only improves soil health but can create an environment less favorable for grubs, as it encourages healthy microbial activity and nematodes that naturally prey on larvae.


Act now to prevent a pest takeover of your lawn

In addition to the above preventive and curative methods, you should ensure proper watering after applying chemical or biological treatments, as it helps them reach the soil and roots where grubs reside. Also, keep an eye on the lawn after treatment, especially if using preventive measures, to check for grub damage and apply curative methods if needed.


Contact us today for a free consultation to discuss how your lawn grubs can be eradicated and your yard can look perfect again.

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