Grub control timing in Ohio and Indiana: preventive vs. curative
Updated October 23, 2026. Live numbers refresh hourly.
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For annual white grubs in Ohio and Indiana, preventive insecticides work best applied in early to mid July, which Purdue calls almost always the optimum timing, while curative treatments are for lawns where sampling in late summer finds damaging numbers or damage has started; spring curative treatment is not recommended.
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Our picks
Chosen from the research below and the makers' own listings. We haven't lab-tested them.
- Homeowner prevention
Scotts GrubEx1 Season Long Grub Killer (99605)
4 moof grub control per application (Scotts)
A once-a-year preventive granular for lawns with a history of grub damage. Scotts' window is spring to early summer; Purdue's optimum is early to mid July, so for annual white grubs put it down toward the end of that window.
- Pros, wider preventive window
Acelepryn G Insecticide (25 lb)
25 lbbag (DoMyOwn)
The professional granular with the same active ingredient class. DoMyOwn's label summary gives early April through early September for preventive and early curative control of the major white grubs, which covers Purdue's July timing.
- Rescue after sampling
BioAdvanced 24 Hour Grub Killer Plus Granules (700740S, 10 lb)
24–48 hactive in soil (DoMyOwn)
A trichlorfon granular for the curative case: when August-to-October sampling finds damaging numbers. It works on contact once watered in and doesn't last, so it's for grubs that are there now, not prevention.
Side by side
| Pick | Best for | Type | Active ingredient | Covers | When (maker or label) | Retailer link |
|---|---|---|---|---|---|---|
| Scotts GrubEx1 Season Long Grub Killer (99605) | Homeowner prevention | Preventive granular | Chlorantraniliprole | 5,000 sq ft per bag (10,000 sq ft size also sold) | Spring to early summer, once a year (Scotts) | Check price at Scotts |
| Acelepryn G Insecticide (25 lb) | Pros, wider preventive window | Preventive and early curative granular | Chlorantraniliprole 0.2% | About 10,000–21,000 sq ft per 25 lb | Early April to early September (label, via DoMyOwn) | Check price at DoMyOwn |
| BioAdvanced 24 Hour Grub Killer Plus Granules (700740S, 10 lb) | Rescue after sampling | Curative granular | Trichlorfon 9.3% | 5,000 sq ft per 10 lb (grubs) | When grubs or damage appear; July–September best (label) | Check price at DoMyOwn |
Types, active ingredients, coverage and timing are from each maker's page or the linked DoMyOwn listing. A dash means the maker doesn't list it.
Scotts GrubEx1 Season Long Grub Killer (99605)
Homeowner prevention
A once-a-year preventive granular for lawns with a history of grub damage. Scotts' window is spring to early summer; Purdue's optimum is early to mid July, so for annual white grubs put it down toward the end of that window.
Why we picked it
- Chlorantraniliprole granules; Scotts says one application protects for up to 4 months.
- Scotts lists Japanese beetle, European chafer, masked chafer and other white grubs, plus billbugs, sod webworms and crane fly larvae.
- Spreader settings are on the page: Scotts broadcast 3 3/4, drop 7 1/4.
Downsides
- Preventive, not a rescue treatment for big late-summer grubs.
- It has to be watered in to reach the root zone; Scotts suggests about a 20-minute soak.
- Keep it off beds, vegetable gardens and areas near ponds or streams (Scotts).
- Type
- Preventive granular
- Active ingredient
- Chlorantraniliprole
- Covers
- 5,000 sq ft per bag (10,000 sq ft size also sold)
- When (maker or label)
- Spring to early summer, once a year (Scotts)
- Model
- Scotts 99605
Acelepryn G Insecticide (25 lb)
Pros, wider preventive window
The professional granular with the same active ingredient class. DoMyOwn's label summary gives early April through early September for preventive and early curative control of the major white grubs, which covers Purdue's July timing.
Why we picked it
- 0.2% chlorantraniliprole from Syngenta (EPA Reg. 100-1500).
- Label rate is 1.15 to 2.3 lb per 1,000 sq ft depending on the pest, so a 25 lb bag covers about 10,000 to 21,000 sq ft (DoMyOwn).
- Goes on with a drop, rotary or handheld spreader.
Downsides
- A 25 lb bag is more than most single lawns need.
- Water it in right after applying, per the label summary on DoMyOwn.
- Not sold to Hawaii or New York (restricted to licensed applicators there).
- Type
- Preventive and early curative granular
- Active ingredient
- Chlorantraniliprole 0.2%
- Covers
- About 10,000–21,000 sq ft per 25 lb
- When (maker or label)
- Early April to early September (label, via DoMyOwn)
- Model
- Syngenta 53199
BioAdvanced 24 Hour Grub Killer Plus Granules (700740S, 10 lb)
Rescue after sampling
A trichlorfon granular for the curative case: when August-to-October sampling finds damaging numbers. It works on contact once watered in and doesn't last, so it's for grubs that are there now, not prevention.
Why we picked it
- 9.3% trichlorfon (Dylox), BioAdvanced 700740S, EPA Reg. 92564-40.
- A 10 lb bag treats 5,000 sq ft for white grubs at 2 lb per 1,000 sq ft (DoMyOwn).
- The label says the best time to kill grubs is July through September, when they're young and feeding near the surface.
Downsides
- Only active for about 24 to 48 hours, per DoMyOwn, so timing and watering matter.
- Water thoroughly within 24 hours; don't use a hand-held or chest-mounted spreader (label).
- No more than 3 applications a year or 1 in any 7 days; not sold to California or Maine.
- Type
- Curative granular
- Active ingredient
- Trichlorfon 9.3%
- Covers
- 5,000 sq ft per 10 lb (grubs)
- When (maker or label)
- When grubs or damage appear; July–September best (label)
- Model
- BioAdvanced 700740S
Know your grubs
Purdue Extension's E-271 describes annual white grubs, including Japanese beetle, masked chafers, European chafer and Oriental beetle, as the most common lawn pests in the group. Ohio State's HYG-2510 notes Ohio has many scarab species whose larvae attack turf roots. Annual species overwinter as larvae, pupate in late spring or early summer, and adults lay eggs in early to mid summer. Eggs hatch by the end of July, and large larvae are present by September.
| Time | Grub stage | Management |
|---|---|---|
| Late spring–early summer | Grubs pupate; adults emerge and fly | Preventive window opens ahead of egg-laying |
| Early–mid July | Egg-laying | Optimum preventive timing (Purdue) |
| End of July | Eggs hatch; small larvae feed | Early curative if sampling finds high numbers |
| August–November | Large larvae; visible damage possible | Late curative (rescue) while grubs feed near surface |
| Winter–spring | Larvae deeper, then return to feed | Spring curative not recommended (K-State) |
Preventive: early to mid July
Preventive products stay active in soil for a long time, so Purdue says they can go down anywhere from several weeks before egg-laying to egg hatch. But applications made far in advance can break down before grubs appear, and Purdue says early-to-mid July is almost always optimum. K-State gives a similar rule: apply four to six weeks before egg hatch. Preventive treatment makes most sense for lawns with a history of grub damage.
Curative: sample first
A few grubs are normal. Purdue says fewer than 5 grubs per square foot rarely need treatment, and some species don't cause visible damage until 10 or more. Cut a few 3-inch-deep sections of sod in July or August and count. NC State notes curative control works when grubs are feeding near the surface, roughly August through October, and recommends irrigating before treatment to bring them up. Watering in afterward moves the product into the root zone.
Late curative treatments lose effectiveness once grubs stop feeding and move deeper for winter, and K-State does not recommend spring curative treatment. If skunks or raccoons are digging, that can be the first sign. For the national soil-timing picture, see soil temperature for lawn care.
Questions
When should I apply grub preventer in Ohio?
Early to mid July is almost always optimum for preventive products against annual white grubs, according to Purdue's E-271.
How many grubs per square foot is too many?
Purdue says fewer than 5 per square foot rarely needs treatment; many species need 10 or more to cause visible damage, though European chafer can damage turf at about 5.
Should I treat grubs in spring?
K-State does not recommend spring curative treatment. Grubs are large and near the end of feeding, and control is poor.
Which grub products are preventive and which are curative?
Chlorantraniliprole products such as Scotts GrubEx1 and Acelepryn G are preventive and last for months. Trichlorfon, in BioAdvanced 24 Hour Grub Killer Plus, is curative: DoMyOwn says it stays active only 24 to 48 hours, so use it after sampling finds damaging numbers.
Bottom line
For annual white grubs in Ohio and Indiana, preventive products work best in early to mid July (Purdue), and they make most sense for lawns with a history of grub damage. Otherwise sample in late summer: fewer than 5 grubs per square foot rarely needs treatment. If counts are high, a curative product applied from August into fall while grubs feed near the surface, watered in, is the rescue option. Skip spring curative treatment.
Check price at ScottsScotts GrubEx1 Season Long Grub Killer (99605)
Sources
- Purdue Extension E-271: Managing White Grubs in Turfgrass
- Ohio State University Extension HYG-2510: Ohio White Grub Adults
- K-State Research and Extension MF3439: Grub Management in Turfgrass Using Insecticides
- NC State Extension: White Grubs in Turf
- Scotts: GrubEx1 Season Long Grub Killer (99605) product page
- DoMyOwn: Acelepryn G Insecticide listing
- DoMyOwn: BioAdvanced 24 Hour Grub Killer Plus Granules listing
Soil temperatures: NOAA GFS model, 0–10 cm layer. Snow: NOAA and National Weather Service. See how we measure.