When is the Best Time to Treat for Grubs on Your Lawn?

Kenneth Wilson

Dealing with a brown, patchy lawn problem? In some cases, grubs may be the culprit behind this. A grub infestation can destroy your turfgrass before you know it, so it’s always best to act on the issue at once. So, if you’re like several other homeowners wondering: “When is the best time to treat for grubs?”

The best time would be between early spring and late summer. Commonly, the extent of grub damage becomes more evident during May, when there’s increasing grub worm activity. When it comes to grub preventers, apply them between June and July (before the hatching season).

When is the Best Time to Treat for Grubs?

The best time to treat grubs will depend on whether you’re preventing young grubs from hatching OR getting rid of the active ones that are causing havoc on your lawn. For grub preventers, apply these products any time between June and July – as this is the time when grubs are about to hatch. This time frame is considered by experts as the most ideal period for preventative grub control.

Meanwhile, if you’re looking into getting rid of existing grub damage, opt to apply your grub killer insecticide of choice on your lawn the moment you notice visible signs of damage. This is usually between early spring to early August, when grub worms are gnawing away at your turfgrass.

When is it too Early to Apply Grub Control?

When it comes to determining the most ideal time in the year to treat the lawn for grubs, keep in mind that there will be a period that’s a little too early. In particular, avoid applying your grub preventer product in the early spring, as this won’t be too effective in preventing grub damage for the following season.

Why? The pesticide will tend to disintegrate into the soil, and will therefore lose potency. When the grubs begin to hatch in July to August– it won’t be effective anymore. Timing is always essential when it comes to determining when to treat your yard for grubs. When done correctly, you can control up to 80 percent of the grubworm infestation.

What to Do After Applying Grub Control Pesticide

Once you’ve applied your pesticide of choice on your lawn, here are several tips to keep in mind shortly after:

  • Opt to water your lawn. Most grub killers in the market today are sold in granular formulations, which means you’ll need to water the lawn immediately after application to at least 1 inch.
  • Continue monitoring for grub worm activity. Applying a grub killer doesn’t translate to instant, fast-action results. In most cases, you can expect to see results after a few days to an entire week.

Important Note: If the damage continues even after applying the pesticide, it means the grub treatment was insufficient or ineffective to handle the infestation. You may want to consult a local professional for their expert services instead.

Natural Methods to Treat Grub Worms

If you’re an environmentally-conscious homeowner that’s not the biggest fan of using commercial pesticides, the good news is– there are several natural methods you can try at home.

  • Introduce natural predators to consume the grubs: In this case, nature will be your best friend. Birds such as blue jays, chickadees, and robins are fond of eating grubs. Some chickens also pick up grubs along the way if you let them graze your backyard. To make it easier for you to invite these wanted natural predators over, install bird feeders and houses in the surrounding area. Bird species will be attracted to drop by your yard and help you keep the grub populations in control.
  • Limit the moisture levels: In order to thrive, grubs will need moisture. So one good way to lessen their population is to create an artificial drought. Ideally, avoid irrigating the lawn for a few weeks sometime in July to kill off both eggs and young grubs.
  • Use Azadirachtin or neem oil: For your reference, neem oil contains little traces of Azadirachtin. So you can opt to apply either of the two on your grub-infested lawn. One study found out that applying Azadirachtin on infested turfgrass can kill the grub worms at 5 times the speed of the product’s label rate. Pure neem oil, on the other hand, is a popular pest control option as it prevents grubs from thriving and laying eggs. Mix these solutions with water and spray them on the affected areas of your lawn.
  • Dethatch and aerate your lawn: Lastly, regular lawn aeration and dethatching make it less appealing in the eyes of grubs. Thatch and compacted soil may become a makeshift shelter for unwanted grubs. As such, you may want to remove thick layers of thatch and aerate your lawn to avoid these pests from taking over your turfgrass.

After detecting the visible presence of lawn grubs, consider immediate treatment and control as a necessity. The best time to treat grub worms is sometime around the late summer or early fall, as the young grub worms are still developing and found near the surface.

Avoid applying your grub treatment in the spring, as lawn grubs usually mature at this point and stop feeding on your grass. Applying insecticides may be ineffective and result in a total waste of your time and money. (Related: Common Florida Yard Pests and How To Prevent Them)

Frequently Asked Questions (FAQs)

Do I need to apply grub control every year?

Unless you see grub damage, you do not need to use grub control every year. If you've been using a grub preventer and killer on your lawn for a few years in a row, it may be advisable to stop until you detect grub indicators once again. Grub preventives aid in grub management for each following season. A grub preventer cannot be used to eliminate grubs that are already causing harm to your lawn. If you use a grub preventer, it won't get rid of any grubs that could be on your lawn between mid-October and mid-May.

What should I look for in grub preventers?

Upon noticing signs of an infestation, most homeowners intend to kill grubs. However, laying down a preventer is the greatest strategy to long-term control their damage. The following active ingredients will be present in an effective grub control preventer: (1) Thiamethoxam, (2) Clothianidin, (3) Imidacloprid, and (4) Chlorantraniliprole. These components should be looked for since they are effective at killing grubs at an early age, typically as soon as they hatch.

How often should I apply grub control?

Grub treatments work best when used at the appropriate time. To completely get rid of grubs on your lawn, you might need to use the insecticide for two or three seasons in a succession. In most cases, grub control must only be used twice in a season. The first is when you detect signs of infestation and the second is using the grub preventer around June and July to halt their cycle.

What are some telling signs of a grub damage on my lawn?

Here are a few obvious indicators that can assist you to identify grub damage on your lawn:

  • Grass turning yellow. Turfgrass becomes spongy and yellow as grubs eat away at the roots. It will roll back like a carpet if you tug on it.
  • Other pest species are present. Their search for grubs, skunks, raccoons, and other tunneling pests will wreak havoc on your lawn. As expensive and challenging to repair as grub damage itself, this damage may be.
  • Moths and beetles are increasing in population. You could have a major grub problem if you've seen a lot of moths or beetles flying around at grass level.
  • The effect of drought. Despite frequent watering, grubs may be the cause of your yard's dry appearance. Grub damage usually resembles drought, but more watering won't make it go away.
  • Grass turns brown and patchy. The grass will turn brown and uneven before it starts to yellow and pull up. The lawn will experience this damage in different locations.
  • There are white grubs present. Cut a square foot section of turf with a spade at a depth of 2-4 inches. Examine the soil beneath the square by pulling it back. Even if you haven't seen any damage to your grass, if you discover grubs, you have an infestation.
Kenneth Wilson
July 12, 2022
2terra, Contractor Tips, Yard & Garden

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

Ask The Author Your Question In The Comments!

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

More From This Author

9 of the Best Ring Security Cameras: Home Security 101
Where You Should Place Security Cameras Around Your Home: Best Locations
How Long Do SimpliSafe Camera Batteries Last?
SimpliSafe vs. Ring: Which Home Security System is Best Suited for Your Needs?
The Best Plug-in Outdoor Security Lights to Keep Your Home Safe
Everything You Need to Know About Residential Laser Grid Security Systems