You’ve spent weekends mowing, watering, and fertilizing your St. Augustine lawn—only to wake up and find spongy brown patches that lift like loose carpet. Chances are, grubs are feasting on the roots beneath your feet.
These white, C-shaped larvae from beetles like June bugs chew through root systems, turning lush grass into peeling turf that birds and raccoons tear apart at night.
We know how frustrating it feels to watch your pride and joy decline despite your best efforts. A healthy St. Augustine lawn isn’t just curb appeal—it’s a living space for family, pets, and pride.
When grubs strike, you need a solution that works fast, targets the problem specifically, and won’t harm your grass type.
Our team analyzed product specs, active ingredients, and real buyer feedback from St. Augustine lawns across warm-season regions. We focused on effectiveness against young grubs, grass safety, application ease, and residual protection.
In this guide, you’ll get clear, no-nonsense recommendations for the best grub killer for St. Augustine grass—so you can stop guessing and start restoring your lawn with confidence.
Quick Comparison
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| 1. Scotts GrubEx1 Season Long Grub Killer, 5,000 sq. ft. |
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| 2. Scotts Turf Builder Weed and Feed 3, 5,000 sq. ft. |
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| 3. TERRO Ant Killer Plus Multi-Purpose Insect Control for Outdoors – Kills Fire Ant |
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| 4. Ortho BugClear Lawn Insect Killer1 – Lawn Bug Killer Granules, Kills Ants, Spide |
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| 5. BioAdvanced Season Long Grub Control Granules – Kills Grubs, Mole Crickets, Cinc |
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Our Top Picks
Best Overall: Scotts GrubEx1 Season Long Grub Killer
Scotts GrubEx1 delivers season-long grub prevention with one spring application and is proven safe for St. Augustine lawns when used correctly.
Best Value: Ortho BugClear Lawn Insect Killer1 – Law
Ortho BugClear provides strong multi-pest control at a lower cost per square foot, ideal for large St. Augustine lawns needing tick and grub defense.
Best Grub Killer For St Augustine Grass: Save Your Lawn – Detailed Reviews
Best Choice
1. Scotts GrubEx1 Season Long Grub Killer
What caught our eye first was Scotts GrubEx1’s ability to prevent grub damage before it starts—critical for St. Augustine grass, which recovers slowly from root loss. This granular formula uses imidacloprid, a systemic insecticide that targets young grubs as they feed, stopping damage early.
One application in spring or early summer protects for up to four months, covering 5,000 sq ft per bag. Buyers report fewer bird diggings and firmer turf after use, confirming real-world results.
Unlike curative treatments that only work on visible damage, GrubEx1 acts preventively, making it ideal for proactive lawn care. It also controls armyworms and chinch bugs—common St. Augustine pests—without harming grass when applied to dry lawns and watered in properly.
Key Features:
- – Imidacloprid-based formula — targets young grubs before they damage roots
- – Season-long protection — one application prevents grubs for up to 4 months
- – Spring application window — ideal timing for St. Augustine’s growth cycle
- – 5,000 sq ft coverage — efficient for medium to large lawns
- – Multi-pest control — also handles armyworms and chinch bugs
Build Quality:
The 14.35 lb bag features a resealable top and sturdy construction that holds up in storage. Granules are uniform in size, ensuring even spread with handheld or broadcast spreaders. Buyers note minimal dust and clumping, which helps prevent over-application. The packaging includes clear instructions specific to St. Augustine grass, including watering guidelines to activate the product without runoff.
Why We Recommend It:
We recommend Scotts GrubEx1 because it prevents grub damage at the most vulnerable stage—when grubs are small and near the surface. Based on buyer feedback and ingredient analysis, it’s one of the few products that balances effectiveness with St. Augustine safety.
Many users saw reduced bird activity and firmer turf within weeks. One limitation: it won’t control large, mature grubs in late summer, so timing matters. Still, for preventive care, it’s the most reliable option we found.
Best For: Best for homeowners who want to apply grub control once in spring and rest easy knowing their St. Augustine lawn is protected through peak grub season.
Who Should Avoid: Avoid if you’re dealing with an active, severe grub infestation in late summer—this product works best preventively, not curatively.
Pros
- – Prevents grub damage before it starts
- – Safe for St. Augustine when applied correctly
- – Long-lasting protection reduces reapplication needs
- – Also controls armyworms and chinch bugs
Cons
- – Not effective against large, mature grubs
- – Requires precise spring timing for best results
Editor’s Choice
5. BioAdvanced Season Long Grub Control Granules
On paper, the numbers look strong — and buyers confirm it: BioAdvanced Season Long Grub Control kills over 40 lawn pests, including grubs, mole crickets, and chinch bugs. Its active ingredient, chlorantraniliprole, creates a protective zone in the soil that stops grubs from feeding within hours.
The 10 lb bag covers up to 10,000 sq ft, making it efficient for larger St.
Augustine lawns. Buyers report visible reduction in grub activity and fewer signs of root damage after mid-summer application.
Key Features:
- – Chlorantraniliprole formula — fast-acting on grubs and mole crickets
- – Barrier protection — creates a zone that stops feeding quickly
- – Broad pest control — targets 40+ lawn insects including ticks and ants
- – 10,000 sq ft coverage — great for large yards
- – Safe for all lawn types — including sensitive St. Augustine
Build Quality:
The granules are fine and free-flowing, spreading evenly with rotary or drop spreaders. The bag is durable with a secure seal, preventing moisture damage. Users note it mixes well with soil when watered in lightly, reducing surface residue. The formula shows low phytotoxicity, meaning it won’t burn St. Augustine blades even in hot weather.
Why We Recommend It:
We recommend BioAdvanced for its dual action: it kills existing small grubs and prevents new ones from causing damage. Buyer feedback highlights success against chafer grubs, a common problem in St. Augustine lawns.
Unlike some products that require multiple apps, this one delivers season-long control. One note: it’s pricier than basic options, but the coverage and effectiveness justify the cost for serious infestations.
Best For: Best for large St. Augustine lawns with a history of grub or mole cricket damage who need strong, long-lasting protection.
Who Should Avoid: Not ideal for small lawns under 3,000 sq ft due to higher cost per use.
Pros
- – Kills grubs and mole crickets effectively
- – Creates lasting soil barrier
- – Safe for St. Augustine in heat
- – Covers large areas efficiently
Cons
- – Higher upfront cost
- – Overkill for minor grub issues
Best Budget
4. Ortho BugClear Lawn Insect Killer1
Compared to premium grub killers, Ortho BugClear offers solid multi-pest control at a fraction of the price. It uses trichlorfon, a fast-acting ingredient that knocks down grubs, ants, ticks, and fleas within minutes. The 10 lb bag treats up to 16,500 sq ft—one of the largest coverages on this list—making it ideal for expansive St.
Augustine lawns. Buyers praise its tick control, especially in wooded or high-grass areas where pets roam.
Key Features:
- – Trichlorfon formula — rapid knockdown of grubs and surface pests
- – 16,500 sq ft coverage — best value for large properties
- – Fast results — starts working in minutes on contact
- – Multi-pest defense — controls ticks, ants, fleas, and grubs
- – Water-activated — requires light watering after application
Build Quality:
Granules are coarse but spread evenly with standard spreaders. The shaker bag is convenient for spot treatments around home perimeters. Some users report slight dust, but overall handling is straightforward. The product is designed for outdoor use only and should not be applied during drought or extreme heat to protect St. Augustine.
Why We Recommend It:
We recommend Ortho BugClear for budget-conscious homeowners with large lawns who face multiple pest threats. While it’s not as long-lasting as preventive options, it’s excellent for curative use when grubs are already visible. Buyers confirm it reduced tick populations significantly.
One drawback: it offers only 3 months of residual protection, so reapplication may be needed in high-pressure areas.
Best For: Best for large St. Augustine lawns needing affordable, broad-spectrum pest control including grubs, ticks, and ants.
Who Should Avoid: Avoid if you prefer long-term prevention—this is better for active infestations.
Pros
- – Low cost per square foot
- – Excellent tick and ant control
- – Large coverage area
- – Fast-acting on contact
Cons
- – Shorter residual protection (3 months)
- – Not ideal for preventive use
Most Versatile
2. Scotts Turf Builder Weed and Feed 3
Buyers keep saying the same thing about this one: Scotts Turf Builder Weed and Feed 3 delivers greening power while tackling weeds—but it’s not a dedicated grub killer. While it feeds St. Augustine and controls dandelions, it lacks active ingredients for grub control.
Some users mistakenly believe weed-and-feed products handle insects, but this one does not target white grubs. It’s great for lawn health, but not for pest problems.
Key Features:
- – Weedgrip Technology — grips visible and hidden weeds
- – Feeds grass to thicken turf — crowds out future weeds
- – Dandelion and clover control — up to 2X stronger than previous formula
- – 5,000 sq ft coverage — matches standard lawn sizes
- – Easy application — works with Scotts spreaders
Build Quality:
The granules are blended evenly, reducing streaking when applied. The bag is sturdy with a resealable top for storage. Users report vibrant green results within two weeks, confirming its fertilizer strength. However, it contains no insecticides, so it won’t stop grubs from damaging roots.
Why We Recommend It:
We do not recommend this as a grub killer—it’s a weed-and-feed product, not an insecticide. It’s excellent for maintaining healthy St. Augustine grass, which can resist pests better, but it won’t eliminate existing grubs.
Use it in rotation with a true grub control product for best results.
Best For: Best for St. Augustine lawns needing weed control and feeding—but only if grubs are not present.
Who Should Avoid: Avoid if you have active grub damage—this product does not kill grubs.
Pros
- – Thickens grass to resist weeds
- – Easy to apply with spreader
- – Visible greening in days
- – Great for routine lawn care
Cons
- – Does not kill grubs or insects
- – Misleading for buyers seeking pest control
Best for Perimeter Defense
3. TERRO Ant Killer Plus Multi-Purpose Insect Control
At this price, we did not expect this level of quality from TERRO Ant Killer Plus—but it excels at perimeter and spot treatment, not lawn-wide grub control. It kills ants, fleas, and roaches fast, with residual repellency that lasts weeks. However, it’s not labeled for grub control in turf, and buyers confirm it doesn’t stop white grubs in St.
Augustine lawns. It’s useful around foundations and ant hills, but not for root-feeding pests.
Key Features:
- – Kills 10+ crawling insects — including fire ants and roaches
- – 24-hour contact kill — fast results on surface pests
- – 3 lb shaker bag — convenient for spot treatment
- – Outdoor use only — safe for lawns when used as directed
- – No spreader needed — sprinkle directly where pests appear
Build Quality:
The shaker bag is well-designed for controlled application. Granules are fine and adhere to soil without blowing away. Users report quick ant elimination around homes. But again, this is not a grub killer—grubs live underground and require soil-penetrating ingredients like imidacloprid or trichlorfon.
Why We Recommend It:
We recommend TERRO for ant and perimeter control, but not for grub management in St. Augustine grass. It’s a helpful add-on if you have ant mounds near your lawn, but it won’t protect roots from grubs.
Use it alongside a true grub control product for full pest defense.
Best For: Best for controlling ants and surface insects around St. Augustine lawns—not for underground grub treatment.
Who Should Avoid: Avoid if your main goal is grub control—this product does not target white grubs.
Pros
- – Fast ant and roach control
- – Easy shaker application
- – Long residual effect
- – Great for home perimeter
Cons
- – Not effective against grubs
- – Limited to surface pests only
How We Researched
Our team started by identifying the core needs of St. Augustine grass owners: grass-safe formulas, effective grub control, proper timing, and real-world results. We analyzed active ingredients, focusing on those proven safe for St. Augustine—like imidacloprid and chlorantraniliprole—while avoiding harsh chemicals that cause burn.
We reviewed product labels, EPA guidelines, and university extension recommendations for warm-season grasses. Then, we examined hundreds of verified buyer reviews from homeowners with St. Augustine lawns, noting patterns in effectiveness, ease of use, and lawn response.
Products were compared on coverage, active ingredient strength, application method, and whether they were preventive or curative. We prioritized options that offered season-long protection with minimal reapplication.
The final picks stood out because they balanced efficacy with grass safety, had strong buyer confirmation of results, and fit real-world lawn care routines. No product was chosen based on marketing claims alone—only data and feedback mattered.
Complete Buying Guide For Best Grub Killer For St Augustine Grass: Save Your Lawn
How to Choose the Right Best Grub Killer For St Augustine Grass
Start by identifying whether you need preventive or curative control. Preventive products like Scotts GrubEx1 work best when applied in spring, before grubs hatch. Curative options like Ortho BugClear act fast on visible damage but require precise timing.
St. Augustine grass is sensitive, so avoid products with harsh chemicals that cause leaf burn.
Look for active ingredients proven safe for St. Augustine: imidacloprid, chlorantraniliprole, or trichlorfon. Check the label for ‘safe for St.
Augustine’ or ‘warm-season grasses.’ Avoid broad-spectrum insecticides not labeled for turf use—they can harm your lawn.
Consider coverage area. A 5,000 sq ft bag suits small yards, while large properties need 10,000+ sq ft options. Granular formulas are easier to control than liquids, reducing runoff risk.
Always use a calibrated spreader for even application.
Watering matters. Most grub killers require light watering after application to move the chemical into the root zone. Never apply during drought or heatwaves—St.
Augustine is already stressed and more vulnerable to damage.
Finally, match grubex for St Augustine grass to your pest type. If you have mole crickets or chinch bugs, choose a broad-spectrum option like BioAdvanced. For pure grub control, stick to targeted formulas.
What We Look For When Reviewing Best Grub Killer For St Augustine Grass
We focus on grass safety first—St. Augustine is prone to chemical burn, so only products labeled safe for this grass type make our list. Effectiveness against young grubs is next; mature grubs are harder to kill and cause more damage.
We prioritize long residual protection to reduce reapplication. Ease of use, coverage area, and real buyer results also factor in. No product is recommended without verified feedback from St.
Augustine lawn owners.
Price vs Quality: What to Expect at Each Budget
Budget options under $25, like Ortho BugClear, offer good curative control but shorter protection. They’re best for large lawns needing fast action. Mid-range products ($25–$40), such as Scotts GrubEx1, provide preventive care with season-long results—ideal for most homeowners.
Premium choices over $40, like BioAdvanced, deliver broad-spectrum control and superior coverage, worth it for high-pressure infestations. Avoid cheap, unlabeled granules—they often lack proper dosing and grass safety testing.
Care & Maintenance Tips
- – Apply grub killer only when soil temperatures reach 60°F—this is when young grubs are active and vulnerable. Use a soil thermometer for accuracy.
- – Never apply during drought or extreme heat. St. Augustine grass is stressed in these conditions and more likely to burn from chemicals.
- – Water lightly after application—about ¼ inch—to activate the product without causing runoff. Avoid heavy watering that washes chemicals below the root zone.
- – Store unused granules in a cool, dry place with the bag tightly sealed. Humidity causes clumping and uneven spreading.
- – Reapply only as directed—most preventive products last 3–4 months. Overuse increases chemical buildup and grass stress.
Frequently Asked Questions
Q: What is the best grubex for St Augustine grass?
Scotts GrubEx1 is the top choice for St. Augustine grass because it prevents grub damage with one spring application and is labeled safe for this grass type.
It uses imidacloprid to target young grubs before they harm roots.
Q: How to kill grubs in St Augustine lawn without burning it?
Use a granular product with imidacloprid or chlorantraniliprole, apply to dry grass in spring, and water lightly after. Avoid liquid sprays and harsh chemicals not labeled for St.
Augustine.
Q: What is the best time to apply grub killer for St Augustine grass?
Apply preventive grub killers in late spring when soil temps reach 60°F—usually April to May in most regions. This targets grubs when they’re small and near the surface.
Q: Can I use trichlorfon on St Augustine grass for grubs?
Yes, trichlorfon is safe for St. Augustine when used as directed.
Ortho BugClear uses this ingredient and works fast on active grub infestations, especially in summer.
Q: Do I need to water after applying grub killer to St Augustine lawn?
Yes, light watering—about ¼ inch—activates granular grub killers and moves the chemical into the root zone. Skip heavy watering to prevent runoff.
Q: Will grub killer harm my St Augustine grass?
Only if misused. Products labeled safe for St.
Augustine, like Scotts GrubEx1, won’t harm grass when applied correctly. Avoid unlabeled or broad-spectrum insecticides.
Q: How do I know if my St Augustine lawn has grubs?
Look for spongy turf that lifts easily, brown patches, and increased bird or raccoon digging. Dig up a small section of soil—if you see 5+ white grubs per square foot, treatment is needed.
Final Verdict
After reviewing specs, ingredients, and real buyer results, our team confidently recommends Scotts GrubEx1 as the best grub killer for St. Augustine grass. It prevents damage early, protects for months, and is proven safe when applied correctly. For large lawns with multiple pests, BioAdvanced offers strong broad-spectrum control. Budget buyers should consider Ortho BugClear for fast curative action.
Best Overall: Scotts GrubEx1 — for reliable, season-long prevention. Best Value: Ortho BugClear — for large lawns needing affordable multi-pest control. Best for Beginners: Scotts Turf Builder Weed and Feed — for routine care (but not grub control).
Check current prices before buying—deals change often, and we verified all pricing at the time of testing. Your St. Augustine lawn deserves the right protection—don’t settle for guesswork.
