Grubs Are Killing My Lawn
White grubs feed on grass roots underground, so the lawn dies from below while the surface still looks thirsty. The catch is timing: the leading product prevents the next generation when it hatches in spring, and it cannot rescue a lawn the current generation is already eating.
The short answer
Scotts GrubEx is the right product, but it has to be used in a different season from the one when most buyers shop for it. Applied in spring, it kills young grubs when they hatch, before root damage starts, and it holds 4.2 stars from 2,342 reviews on Home Depot (November 2026). Applied to a lawn already peeling back in fall, it cannot save that grass, and its own review record says so repeatedly. Buy it for next year's lawn, and accept that this year's damage needs repair, not this product.
Why does this happen?
Grubs are beetle larvae living in the soil, feeding on roots. A lawn can carry a few without harm, but at damaging numbers, around 8 to 10 grubs per square foot on extension guidance, the roots are eaten faster than they regrow and the turf starves in expanding patches that feel spongy and lift like a carpet, because almost nothing is anchoring it. Animals deliver the other clue: skunks, raccoons, and birds dig up infested lawns to eat the grubs, so sudden night digging in late summer often reports the infestation before the owner finds it.
The calendar is the trap here. Damage shows in late summer and fall, when grubs are large and feeding hard. That is when a preventive aimed at newly hatched grubs has nothing to work on, because older larvae survive what kills a hatchling. Prevention runs the other way: treat in spring, the product waits in the soil, eggs hatch into it, and the damaging generation never gets established. Buying in spring for a problem you feel in fall is backwards from normal shopping. That is why the product collects bad reviews from people who used it as a cure, which it never claimed to be, and why timing comes first on this page.
The fix, in order
Work down the list: free and cheap steps first. Stop when the plant turns the corner; the product is only for what the free steps cannot do.
Free step
Peel back a square foot and count
At the edge of a brown patch, cut three sides of a one foot square of turf and fold it back. Count the white, curled grubs in the soil beneath. Around 8 to 10 or more per square foot confirms a damaging infestation; one or two means look elsewhere for the cause, at drought, disease, or dog damage, before spending anything on grubs.
Free step
Accept this season loss honestly and repair it
Roots already eaten do not regrow because a product arrives. Rake out dead turf, reseed or overseed the patches, and water the new seed as it establishes. This is the unglamorous repair for the current year, and doing it promptly matters more than which rescue product promises otherwise, because no preventive rebuilds a root system that is already gone.
The product step
Apply GrubEx in spring, before hatch
Spread Scotts GrubEx at the label rate in spring, timed so it is in the soil when beetle eggs hatch and young grubs are at their most vulnerable. Water it in as directed so the granules leave the surface and reach the soil zone where hatchlings feed. This single timed application is the whole strategy. The same bag applied in fall is wasted money.
The product for this step
Scotts GrubEx
Habit step
Check the diggers and the sponge test each fall
Each late summer, walk the lawn for the two signs: turf that feels spongy or lifts easily, and fresh digging by animals after the grubs themselves. Catching a rising population at the count stage, before patches spread, keeps next spring decision informed instead of desperate, and a simple note of the count each year shows whether prevention is holding.
The evidence, in tiers
Tier 1 · The method
Extension guidance supports both halves of the method: the roughly 8 to 10 grubs per square foot threshold for deciding treatment is warranted, and the preventive timing, treating so the product is active when eggs hatch, because older grubs are far harder to kill. The mechanism and the product claims agree.
Tier 2 · This product
Scotts GrubEx holds 4.2 stars from 2,342 reviews on Home Depot (November 2026), and that record itself states repeatedly that the product is preventive rather than a cure.
We have not run a treated and untreated plot through a grub season for this guide. The timing and threshold guidance follows extension practice and the product label.
Tier 3 · What owners report
Owners who applied in spring report the quiet success of a problem that never appears. The negative pattern is remarkably consistent: fall buyers treating visible damage, seeing no recovery, and rating the product for failing a job it states it cannot do, with a smaller set reporting weak results they attribute to their soil.
The alternatives, conceded where they win
| Option | What it is | The honest verdict |
|---|---|---|
| Scotts GrubEx | Preventive treatment active at hatch | The pick for breaking the cycle: timed in spring, it stops the damaging generation before it feeds, and its record reflects exactly that use. |
| A curative grub killer for active grubs | Treatment aimed at grubs already feeding | Wins for this season emergency: when grubs are large, feeding, and confirmed by the count, a product aimed at active grubs is the tool GrubEx is not. It loses as a yearly plan, because it fights the expensive generation instead of preventing it. |
| Reseeding and repair only | Remove dead turf, reseed, and water | Wins on honesty for a lawn below the grub threshold or already past saving: seed and water rebuild what is actually missing. It loses when a real infestation is confirmed, because new roots planted into a grub population become next season damage. |
The honest price comparison
Compare one spring bag with the cycle most owners are stuck in: fall damage, a rescue product that cannot rescue, reseeding into a surviving grub population, and the same bill again next year. Prevention feels unrewarding in the spring you buy it, and looks cheap by the second fall.
Where it falls short
These weaknesses come from the product's own reviews, not from a rival's marketing. Read them before you buy.
- It is preventive, not a cure, and the gap between that fact and buyer expectation in fall is the largest single theme in its negative reviews.
- Its season is unforgiving in the opposite direction from most products: bought in the season the damage is visible, it is simply too late, and no application rate changes that.
- The record documents weaker results in some soil types, so a correct spring application is a strong bet rather than a guarantee.
The product, in short
Scotts GrubEx
Questions people ask next
Can GrubEx save the lawn I have now?
No. It kills young grubs when they hatch and does nothing for roots already eaten or the large grubs eating them. Repair the current damage with seed and water, and use GrubEx in spring to stop the next generation. They are two separate jobs, in two seasons, with two different tools.
How do I know it is grubs and not drought?
Peel back a square foot at a patch edge and count: around 8 to 10 or more grubs confirms it. Grub damaged turf also lifts like carpet because the roots are gone, and animals digging at night for the grubs is a supporting sign drought never produces.
When in spring should it go down?
Early enough that it is in the soil and active before beetle eggs hatch, following the label timing for your area. The principle matters more than a single date: prevention only works when it precedes the hatch, and a late application meets grubs already too old to be its target.
Animals are digging up my lawn. Is that grubs?
Very often, yes: skunks, raccoons, and birds dig for grubs, and sudden night digging in late summer is a classic report of a heavy population. Confirm with the square foot count before treating, since the same animals occasionally dig for other food, and the count decides.
Home Depot product record for Scotts GrubEx (November 2026) · Extension service guidance on grub thresholds and preventive timing
The Fix JournalCase 12Plants & Garden