Marathon grass is a popular cool-season turfgrass variety widely used in lawns due to its rich green color, durability, and lush appearance. However, like any turf, it faces constant threats from weeds that can choke its growth, weaken its roots, and ruin its visual appeal.
Choosing the best weed killer for Marathon grass is essential for maintaining a healthy, thriving lawn that looks attractive year-round.
When selecting a weed killer, it’s important to ensure that the product is safe for Marathon grass while being strong enough to eliminate invasive weeds such as crabgrass, dandelions, clover, and other broadleaf or grassy intruders.
This detailed guide provides the 20 best weed killers for Marathon grass, each carefully chosen for effectiveness, safety, and value to help you make the right choice for your lawn. Homeowners and landscapers often struggle to balance weed control with protecting the turf.
10 Best Weed Killer For Marathon Grass
1. Scotts Turf Builder Weed and Feed – Best Overall
Scotts Turf Builder Weed and Feed is one of the most popular lawn care products that works well on Marathon grass. It kills weeds while simultaneously feeding your turf, promoting stronger roots and greener growth. This dual action ensures your lawn remains weed-free and vibrant throughout the growing season.
The product is especially effective on broadleaf weeds like dandelions and clover. Its WeedGrip technology allows it to latch onto weeds, even the small ones you can’t see, ensuring complete removal. The fertilizer component strengthens your grass, giving it the nutrients it needs to outcompete future weeds.
Applying this product twice a year can make a noticeable difference in the density and health of your Marathon grass. It’s easy to use, safe when applied correctly, and offers visible results within a few weeks.
Pros:
• Kills broadleaf
• Feeds lawn
• Easy application
• Strengthens turf
• Works fast
• Trusted brand
• Covers large area
Cons:
• Pricey option
• Not organic
• Timing sensitive
2. Ortho Weed B Gon Weed Killer – Best Spot Treatment
Ortho Weed B Gon is a great solution for targeting weeds without harming Marathon grass. It kills weeds right down to the roots, ensuring they don’t return quickly. This makes it perfect for homeowners who want precise weed control.
It works on over 200 common lawn weeds, including crabgrass, chickweed, dandelions, and clover. The selective formula ensures it spares your turf while attacking weeds aggressively. For best results, apply during active weed growth when temperatures are moderate.
Its fast action makes it a favorite for spot treatments rather than whole-lawn applications. Marathon grass responds well to this product, as it eliminates competition and allows the turf to thrive.
Pros:
• Root kill
• Targets weeds
• Fast action
• Safe on turf
• Easy spray
• Long-lasting
• Works on many
Cons:
• Limited area
• May need reapply
• Not pre-emergent
3. Spectracide Weed Stop For Lawns – Best for Quick Results
Spectracide Weed Stop offers quick results for Marathon grass lawns that need fast weed control. It begins working within hours of application and shows visible results in just a day. This makes it a convenient choice for busy homeowners.
The formula targets more than 200 broadleaf weeds, including stubborn varieties like chickweed and dandelions. Unlike some weed killers, it’s designed to be rainproof within a few hours, so you don’t need to worry about watering interfering.
Its affordability and ease of use make it highly attractive. With consistent application, it allows Marathon grass to maintain its lush, uniform appearance.
Pros:
• Works fast
• Rainproof quick
• Affordable option
• Broad coverage
• Easy spray
• Kills many weeds
• Good for lawns
Cons:
• Needs repeat
• Not organic
• Limited pre-control
4. Roundup For Lawns – Best for Large Areas
Roundup For Lawns is specially formulated to be safe for Marathon grass while tough on weeds. It differs from traditional Roundup designed for total vegetation kill, making it a great choice for selective weed control.
This product works on over 90 types of common weeds, including crabgrass and dandelions. It covers large areas efficiently, which is ideal for bigger lawns that need thorough treatment.
Rainproof in just four hours, it offers dependable results in a relatively short time. When applied correctly, it provides a weed-free and lush turf.
Pros:
• Covers large area
• Safe on turf
• Rainproof quick
• Effective selective
• Trusted brand
• Easy to use
• Long-lasting
Cons:
• Higher cost
• Multiple apps
• Not organic
5. Preen Lawn Weed Control – Best Preventative
Preen Lawn Weed Control is excellent for preventing weeds before they even appear. This pre-emergent herbicide is designed to stop crabgrass and other weeds from germinating.
It’s best applied in early spring to Marathon grass, ensuring a season-long defense. This product is particularly effective for homeowners who prefer to tackle weed problems early rather than reactively.
When used consistently, Preen helps maintain a clean, uniform lawn without weeds interfering with grass growth. It works well alongside regular lawn maintenance practices.
Pros:
• Prevents weeds
• Easy apply
• Season-long control
• Works on crabgrass
• Safe on turf
• Saves time
• Reliable results
Cons:
• Not post-kill
• Timing critical
• May miss some
6. BioAdvanced Weed and Crabgrass Killer – Best for Crabgrass
BioAdvanced offers a specialized solution for lawns struggling with crabgrass infestations. It kills both crabgrass and over 200 broadleaf weeds while sparing Marathon grass.
The product works systemically, traveling down to the roots of the weeds. This ensures long-term elimination rather than temporary surface-level control.
Its dual action makes it ideal for lawns that often deal with both grassy and broadleaf invaders. Marathon grass benefits from the selective action that leaves it unharmed.
Pros:
• Kills crabgrass
• Broad coverage
• Systemic kill
• Long-lasting
• Selective formula
• Easy to apply
• Strong results
Cons:
• Needs timing
• Weather sensitive
• Not organic
7. Southern Ag 2,4-D Amine – Best Professional Choice
Southern Ag’s 2,4-D Amine weed killer is often used by lawn care professionals for stubborn weed infestations. It works on a wide range of broadleaf weeds without damaging Marathon grass.
The product is highly concentrated, so it requires dilution and careful application. While this may take extra effort, it offers long-lasting and effective results.
For large properties or persistent weed problems, it provides a cost-effective solution. Homeowners who want commercial-level results often turn to this option.
Pros:
• Professional grade
• Kills broadleaf
• Cost-effective
• Concentrated formula
• Long-lasting
• Works fast
• Versatile use
Cons:
• Needs dilution
• Careful handling
• Strong odor
8. Green Gobbler Vinegar Weed Killer – Best Organic Option
Green Gobbler is an organic weed killer that uses vinegar as its active ingredient. While non-selective, it can be carefully applied to weeds in Marathon grass without harming the turf if used precisely.
It’s biodegradable and safe for children and pets once dry. Many eco-conscious homeowners prefer it over chemical herbicides.
Although it works best on young weeds, it provides a safe and natural alternative. With careful spot treatment, Marathon grass lawns remain unharmed.
Pros:
• Organic option
• Pet safe
• Biodegradable
• Eco-friendly
• Works fast
• Non-toxic
• Easy apply
Cons:
• Non-selective
• Multiple sprays
• Limited root kill
9. Tenacity Herbicide – Best Pre- and Post-Emergent
Tenacity Herbicide is a professional-grade product that works as both a pre-emergent and post-emergent. It provides excellent control of crabgrass and other invasive weeds while being safe on Marathon grass.
It works by inhibiting photosynthesis in weeds, eventually killing them off. Applied correctly, it offers long-lasting protection throughout the season.
Though more expensive than other products, its versatility and strength make it worthwhile. Marathon grass thrives under its broad protection.
Pros:
• Pre/post control
• Kills crabgrass
• Long-lasting
• Professional grade
• Effective systemic
• Safe on turf
• Versatile use
Cons:
• Expensive option
• Needs care
• Limited supply
10. Ferti-Lome Weed-Out – Best for Dandelions
Ferti-Lome Weed-Out is a great choice for eliminating stubborn dandelions and clover in Marathon grass. It targets over 200 types of weeds selectively.
This product kills down to the root, ensuring weeds don’t regrow. Its fast action is noticeable within days, restoring a clean lawn.
It’s easy to apply and safe when used according to directions. Many homeowners appreciate its efficiency in restoring thick turf.
Pros:
• Kills dandelions
• Fast action
• Root kill
• Easy apply
• Safe selective
• Affordable choice
• Works widely
Cons:
• Weather dependent
• Needs repeat
• Not organic
11. Bayer Advanced Southern Weed Killer – Best for Warm Climates
This Bayer weed killer is specially designed for lawns in warmer climates, including Marathon grass. It controls a variety of broadleaf weeds effectively.
Its selective formula ensures the turf remains unharmed. The product is rainproof within hours, ensuring dependable performance.
Perfect for southern homeowners, it maintains healthy lawns even in challenging conditions. Marathon grass remains thick and weed-free with consistent application.
Pros:
• Warm-climate safe
• Rainproof quick
• Selective control
• Easy to use
• Reliable results
• Trusted brand
• Effective broadleaf
Cons:
• Limited regions
• May need reapply
• Not organic
12. Bonide Weed Beater Ultra – Best Cool-Weather Option
Bonide Weed Beater Ultra works well in cool weather conditions, making it ideal for Marathon grass in transitional seasons. It provides visible results even when temperatures are lower.
The formula controls a broad spectrum of weeds without damaging the turf. It’s effective against dandelions, clover, and plantain.
Homeowners who need weed control outside peak summer benefit from this product. It ensures year-round care for Marathon grass.
Pros:
• Cool-weather use
• Works fast
• Selective formula
• Broad coverage
• Easy spray
• Trusted brand
• Root kill
Cons:
• Weather sensitive
• Needs repeat
• Not organic
13. Compare-N-Save Concentrate – Best Budget Option
Compare-N-Save offers an affordable weed killer for large areas of Marathon grass. This concentrated formula delivers effective results at a fraction of the cost.
Though it requires careful mixing, the value is unmatched. It provides lasting weed control when applied properly.
For budget-conscious homeowners, it’s a practical way to manage weeds without overspending. Marathon grass thrives with consistent use.
Pros:
• Affordable choice
• Concentrated formula
• Lasting control
• Covers large area
• Easy availability
• Works well
• Strong results
Cons:
• Needs mixing
• Careful use
• Non-organic
14. Gordon’s Trimec Lawn Weed Killer – Best for Broad Coverage
Gordon’s Trimec is a powerful herbicide designed for broadleaf weed control in lawns like Marathon grass. It eliminates dandelions, chickweed, and clover effectively.
The formula works systemically, killing weeds from the inside out. It provides visible results within weeks.
Homeowners prefer it for consistent performance and professional-level results. It’s safe when applied correctly on Marathon grass.
Pros:
• Kills broadleaf
• Systemic action
• Fast results
• Reliable product
• Professional grade
• Selective safe
• Cost-effective
Cons:
• Needs dilution
• Not organic
• Weather limited
15. Hi-Yield Atrazine Weed Killer – Best for Persistent Weeds
Hi-Yield Atrazine is excellent for controlling persistent weeds in Marathon grass. It acts as both a pre-emergent and post-emergent herbicide.
This dual action provides lasting protection against crabgrass and other invasive weeds. Its selective formula ensures turf remains unharmed.
It’s especially valuable in areas where weeds constantly reappear. Marathon grass benefits from long-term weed management.
Pros:
• Dual action
• Lasting control
• Selective safe
• Effective crabgrass
• Pre/post-emergent
• Easy apply
• Affordable option
Cons:
• Not organic
• Needs timing
• May need repeat
16. Image Herbicide – Best for Nutsedge
Image Herbicide is specially formulated to control nutsedge, a tough weed common in many lawns. It works well on Marathon grass without causing damage.
This product attacks the tubers of nutsedge, ensuring long-lasting control. It’s rainproof within hours and offers reliable results.
For lawns plagued by nutsedge, this product is highly recommended. Marathon grass remains lush and uniform when nutsedge is eliminated.
Pros:
• Kills nutsedge
• Long-lasting
• Selective safe
• Rainproof quick
• Effective control
• Easy apply
• Trusted brand
Cons:
• Limited spectrum
• May need repeat
• Not organic
17. MSM Turf Herbicide – Best for Clover
MSM Turf Herbicide is highly effective against clover infestations in Marathon grass lawns. It provides systemic control that kills weeds at the root.
The product works well in small doses, making it cost-effective for long-term use. It ensures your grass stays weed-free for weeks.
Many professionals rely on it for targeted weed management. Marathon grass benefits from its selective and strong action.
Pros:
• Kills clover
• Systemic action
• Cost-effective
• Professional grade
• Long-lasting
• Works fast
• Selective safe
Cons:
• Strong formula
• Needs care
• Not organic
18. Drive XLR8 Crabgrass Killer – Best for Speedy Crabgrass Control
Drive XLR8 is a liquid crabgrass killer that works quickly and effectively on Marathon grass. It’s designed for fast absorption and systemic control.
This product eliminates crabgrass and other grassy weeds without damaging turf. It’s rainproof in hours and shows results within days.
Ideal for homeowners battling crabgrass infestations, it restores lawns quickly. Marathon grass thrives when crabgrass competition is eliminated.
Pros:
• Fast absorption
• Kills crabgrass
• Rainproof quick
• Systemic control
• Long-lasting
• Selective safe
• Professional grade
Cons:
• Expensive option
• Needs sprayer
• Not organic
19. Sedgehammer Herbicide – Best for Yellow Nutsedge
Sedgehammer is another excellent option for controlling yellow nutsedge in Marathon grass. It provides long-term control of one of the most difficult weeds to eliminate.
Its systemic action ensures the plant and its tubers are killed. Safe on turf, it prevents re-infestation when used consistently.
For stubborn nutsedge issues, Sedgehammer is a proven choice. Marathon grass remains clean and healthy after treatment.
Pros:
• Kills nutsedge
• Long-term results
• Systemic action
• Selective safe
• Easy apply
• Trusted brand
• Professional grade
Cons:
• Pricey option
• Limited weeds
• Needs patience
20. Syngenta Barricade Pre-Emergent – Best Long-Term Prevention
Syngenta Barricade is a professional-grade pre-emergent herbicide ideal for Marathon grass. It prevents crabgrass and other invasive weeds from germinating.
This long-term solution works for months after application. It’s highly effective for homeowners who want proactive weed control.
Though it doesn’t kill existing weeds, its preventative power is unmatched. Marathon grass lawns stay thick and uniform all season.
Pros:
• Long-term control
• Professional grade
• Prevents weeds
• Safe on turf
• Effective crabgrass
• Works months
• Reliable product
Cons:
• Not post-kill
• Expensive option
• Timing critical
Weed Killers for Marathon Grass FAQs
1. What is the best time to apply weed killer on Marathon grass?
The best time is during active weed growth, typically in spring and early fall. Applying when temperatures are mild helps avoid stressing the turf. Pre-emergent herbicides should be applied early in spring before weeds germinate.
2. Can weed killers damage Marathon grass?
Selective weed killers are designed to spare Marathon grass while targeting weeds. However, improper application or overdosing can harm the turf. Always follow the manufacturer’s instructions carefully.
3. How often should I apply weed killers to my lawn?
Most post-emergent weed killers should be applied once or twice per season. Pre-emergents may need reapplication every 3–6 months depending on product duration. Consistent but careful use is key.
4. Are organic weed killers safe for Marathon grass?
Yes, organic options like vinegar-based solutions are safe when applied carefully. However, most are non-selective, so spot treatment is essential to avoid harming turf. They may also require more frequent applications.
5. What weeds commonly affect Marathon grass?
Marathon grass is often invaded by crabgrass, clover, dandelions, chickweed, nutsedge, and plantain. These weeds compete for nutrients and weaken the turf if not managed properly.
6. Should I water after applying weed killer?
Some products require watering to activate, while others need dry time to absorb. Always check the product label for specific instructions. Overwatering can reduce effectiveness.
7. Can I use weed and feed products on Marathon grass?
Yes, many weed and feed products are safe for Marathon grass. They help eliminate weeds while providing essential nutrients. Apply only as directed to avoid turf stress.
Conclusion
Maintaining Marathon grass requires careful weed management to keep it lush, green, and healthy. The 20 best weed killers for Marathon grass listed above offer a wide range of solutions, from pre-emergents and post-emergents to organic options. Each product has its strengths, making it suitable for different lawn care needs.
By selecting the right weed killer, you can eliminate invasive weeds without harming your Marathon turf. Consistent application and proper timing ensure your lawn stays thick, vibrant, and weed-free.
If you’re ready to take your lawn care to the next level, choose a product that fits your needs and apply it correctly. Your Marathon grass will reward you with a stunning, healthy appearance that stands out.