Finding a herbicide that kills grass but not broadleaf plants is essential when grassy weeds invade flower beds, vegetable plots, and ornamental borders. Standard weed killers often damage desirable plants, so selective products that target grasses while leaving broadleaf species unharmed are genuinely valuable tools.
These selective herbicides work because grasses and broadleaf plants have different physiology, allowing chemicals to target one group without harming the other. Gardeners, landscapers, and groundskeepers use them to remove couch grass, crabgrass, and other invasive grasses from beds where desirable broadleaf plants are growing.
The key to success lies in choosing the correct active ingredient for the grass species, applying at the right growth stage, and protecting nearby desirable grasses from accidental spray drift. With careful use, these products clear grass without damaging the plants you want to keep.
This guide reviews 15 of the best herbicides that kill grass but not broadleaf plants, chosen for their effectiveness, selectivity, and suitability for garden and landscape use.
15 Best Herbicide That Kills Grass But Not Broadleaf
1. Fluazifop-P-Butyl – Best Overall Herbicide That Kills Grass But Not Broadleaf
Fluazifop-P-Butyl is the best overall herbicide that kills grass but not broadleaf because it targets grassy weeds with exceptional selectivity while leaving broadleaf plants completely unharmed. This systemic graminicide is a favourite for clearing grass from flower beds and ornamental borders.
- TARGET GRASSY WEEDS WITH FAST-ACTING VENDRA II: Vendra II herbicide is formulated with 24.5% fluazifop-p-butyl to selectively target grassy weeds without damaging desirable grass and ornamental plants.
- POWER OVER PROBLEMATIC GRASSY WEEDS: Vendra II acts quickly on many annual and perennial grassy weeds including bermudagrass, barnyardgrass, crabgrass, foxtail, quackgrass, and more. See the product label for complete control list.
The active ingredient moves systemically through the grass plant, reaching rhizomes and stolons so couch grass and other perennial grasses die completely rather than regrowing. Broadleaf plants lack the target enzyme, so they remain unaffected even when sprayed directly. Therefore, it offers complete grass control with genuine broadleaf safety.
Apply fluazifop-P-butyl as a foliar spray when grasses are actively growing and not under drought stress. Avoid spraying desirable grasses, and use a shield or careful directed application near lawn edges. Overall, it is the most reliable selective grass killer for mixed plantings.
Pros:
- Excellent grass selectivity
- Systemic action kills rhizomes
- Safe on broadleaf plants
- Effective on couch and crabgrass
- Rainfast within hours
- Works in most conditions
- Widely available
Cons:
- Toxic to desirable grasses
- Slow visible results
- Requires careful application
2. Sethoxydim – Best Fast-Acting Grass-Only Herbicide
Sethoxydim is the best fast-acting grass-only herbicide because it delivers visible results within days while remaining safe on broadleaf plants. This systemic graminicide is a favourite for quick clearance of annual and perennial grasses.
- This selective grass killer is designed to target both annual and perennial grass weeds.
- The product can be applied to around vegetables, gardens, trees, shrubs and ornamentals safely.
The active ingredient is absorbed by grass foliage and moves to growing points, stopping growth quickly and causing collapse within a week. Broadleaf species lack the target site and remain completely unaffected. Therefore, it offers rapid grass control with genuine broadleaf safety.
Apply sethoxydim as a directed foliar spray when grasses are young and actively growing for best results. Add a crop oil concentrate to improve absorption, especially on tougher grass species. Overall, it is the best choice when fast results are needed.
Pros:
- Fast visible results
- Excellent grass selectivity
- Systemic action
- Safe on broadleaf plants
- Effective on annual grasses
- Works on perennial grasses
- Widely available
Cons:
- Toxic to desirable grasses
- Needs crop oil additive
- Requires repeat applications on tough grasses
3. Clethodim – Best Herbicide For Dense Grass Infestations
Clethodim is the best herbicide for dense grass infestations because it controls even tough perennial grasses and volunteer cereals in heavily infested beds. This systemic graminicide is a favourite for commercial and agricultural broadleaf crops.
The active ingredient moves through grass foliage to growing points, killing rhizomes and preventing regrowth from underground structures. It is safe on a huge range of broadleaf crops including vegetables, ornamentals, and legumes. Therefore, it offers reliable control of even the toughest grass species.
Apply clethodim as a foliar spray with a crop oil concentrate or non-ionic surfactant for best absorption. Spray when grasses are actively growing and not drought-stressed for maximum effectiveness. Overall, it is the best choice for severe grass infestations in broadleaf crops.
Pros:
- Controls tough perennial grasses
- Safe on many broadleaf crops
- Systemic kills rhizomes
- Effective on volunteer cereals
- Rainfast within an hour
- Works in a wide temperature range
- Excellent value
Cons:
- Toxic to desirable grasses
- Needs surfactant for best results
- Slow visible knockdown
4. Quizalofop-P-Ethyl – Best Herbicide For Couch Grass Control
Quizalofop-P-Ethyl is the best herbicide for couch grass control because it targets this notoriously difficult rhizomatous grass without harming broadleaf plants. This systemic graminicide is a favourite for clearing couch grass from flower beds and borders.
The active ingredient moves through grass foliage and rhizomes, killing the entire couch grass network rather than just the top growth. Broadleaf plants lack the target enzyme, so they remain unaffected even when sprayed directly. Therefore, it offers thorough couch grass control with genuine broadleaf safety.
Apply quizalofop-P-ethyl as a foliar spray when couch grass has plenty of leaf surface for absorption and is actively growing. Reapply after six to eight weeks if regrowth appears from surviving rhizomes. Overall, it is the best targeted choice for couch grass in mixed plantings.
Pros:
- Excellent on couch grass
- Kills rhizome networks
- Safe on broadleaf plants
- Systemic action
- Rainfast within an hour
- Effective at low rates
- Widely available
Cons:
- Toxic to desirable grasses
- May need repeat applications
- Requires careful timing
5. Fenoxaprop-P-Ethyl – Best Herbicide For Crabgrass And Annual Grasses
Fenoxaprop-P-Ethyl is the best herbicide for crabgrass and annual grasses because it targets these common weeds selectively while leaving broadleaf plants unharmed. This systemic graminicide is a favourite for vegetable plots and ornamental beds.
The active ingredient is absorbed by grass foliage and moves to growing points, stopping cell division and causing rapid collapse. It is safe on a range of broadleaf crops including brassicas, legumes, and ornamentals. Therefore, it offers reliable annual grass control with genuine broadleaf safety.
Apply fenoxaprop-P-ethyl when annual grasses are young and actively growing, before they set seed. Spray under cool conditions and avoid application during drought or heat stress. Overall, it is the best choice for crabgrass and annual grass control in broadleaf plantings.
Pros:
- Excellent on crabgrass
- Safe on broadleaf crops
- Works at low temperatures
- Fast-acting
- Systemic action
- Effective on annual grasses
- Good value
Cons:
- Toxic to desirable grasses
- Limited on perennial grasses
- Needs young weeds for best results
6. Fluazifop-P-Butyl + Fenoxaprop Mix – Best Combination Herbicide
Fluazifop-P-Butyl + Fenoxaprop Mix is the best combination herbicide because it pairs two selective graminicides for broader grass control in one application. This combined product is a favourite for mixed annual and perennial grass problems.
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The combination targets both annual grasses like crabgrass and perennial grasses like couch grass, offering broad-spectrum control in a single spray. Both actives are safe on broadleaf plants, so desirable species remain protected. Therefore, it offers comprehensive grass control with genuine broadleaf safety.
Apply the mixture as a foliar spray when grasses are actively growing and not under drought stress. Use a surfactant to improve absorption on tough grass species. Overall, it is the best choice when both annual and perennial grasses need control.
Pros:
- Controls annual and perennial grasses
- Safe on broadleaf plants
- Single application
- Broad-spectrum activity
- Systemic action
- Convenient formulation
- Good value
Cons:
- Toxic to desirable grasses
- Higher cost than single actives
- Requires careful timing
7. Alloxydim – Best Herbicide For Grass In Ornamental Beds
Alloxydim is the best herbicide for grass in ornamental beds because it controls grassy weeds selectively while leaving shrubs, perennials, and broadleaf flowers unharmed. This systemic graminicide is a favourite for landscape maintenance.
- This weed killer safe for grass and kills the weeds not the lawn when used as directed
- Fast acting post emergent weed control for lawns, see results in hours
The active ingredient is absorbed by grass foliage and moves to growing points, killing grasses from within without harming neighbouring ornamentals. It is safe on a wide range of broadleaf shrubs and perennials. Therefore, it offers reliable grass control in mixed ornamental plantings.
Apply alloxydim as a directed foliar spray when grasses are actively growing and not under stress. Shield desirable grasses with cardboard or plastic during application. Overall, it is the best choice for grass control in ornamental borders and shrub beds.
Pros:
- Safe on ornamentals
- Systemic action
- Controls many grass species
- Effective at low rates
- Rainfast quickly
- Suits landscape use
- Widely available
Cons:
- Toxic to desirable grasses
- Requires careful shielding
- Slow visible results
8. Tepraloxydim – Best Herbicide For Grass In Vegetable Crops
Tepraloxydim is the best herbicide for grass in vegetable crops because it controls grassy weeds without harming broadleaf vegetables such as beans, brassicas, and root crops. This systemic graminicide is a favourite for commercial vegetable production.
- Transline Clopyralid Specialty Herbicide controls broadleaf weeds and woody brush species in non-crop areas, forest sites, industrial manufacturing and storage sites, rights-of-way, and wildlife openings, including grazed areas on these sites, tree plantations, and rangeland and permanent grass pastures.
The active ingredient moves through grass foliage to growing points, killing grasses from within while leaving broadleaf vegetables untouched. It is effective on annual and perennial grasses at relatively low rates. Therefore, it offers reliable grass control with genuine vegetable crop safety.
Apply tepraloxydim as a directed foliar spray when grasses are young and actively growing. Observe pre-harvest intervals for the specific crop being treated. Overall, it is the best choice for grass control in broadleaf vegetable production.
Pros:
- Safe on broadleaf vegetables
- Controls many grass species
- Systemic action
- Effective at low rates
- Rainfast quickly
- Suits commercial crops
- Reliable results
Cons:
- Toxic to desirable grasses
- Requires pre-harvest timing
- Limited retail availability
9. Propaquizafop – Best Herbicide For Volunteer Cereals
Propaquizafop is the best herbicide for volunteer cereals because it controls self-sown wheat, barley, and oats selectively in broadleaf crops. This systemic graminicide is a favourite for agricultural and horticultural rotations.
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The active ingredient moves through grass foliage to growing points, killing volunteer cereals and other grasses while leaving broadleaf crops unharmed. It is effective at low rates and works well in cool conditions. Therefore, it offers reliable volunteer cereal control with genuine broadleaf crop safety.
Apply propaquizafop as a foliar spray when volunteer cereals are young and actively growing. Use a surfactant to improve absorption on tough grass species. Overall, it is the best choice for volunteer cereal control in broadleaf rotations.
Pros:
- Excellent on volunteer cereals
- Safe on broadleaf crops
- Works in cool conditions
- Effective at low rates
- Systemic action
- Suits crop rotations
- Reliable results
Cons:
- Toxic to desirable grasses
- Needs young weeds
- Limited retail availability
10. Fluazifop-P-Butyl Concentrate – Best Value Grass-Only Herbicide
Fluazifop-P-Butyl Concentrate is the best value grass-only herbicide because it delivers reliable selective grass control at an economical price. This concentrated formulation is a favourite for large beds and repeated applications.
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The concentrated liquid is diluted with water and applied as a foliar spray, providing reliable grass control at low cost per square metre. It is safe on broadleaf plants and effective on both annual and perennial grasses. Therefore, it offers dependable grass control at excellent value.
Dilute fluazifop concentrate according to label rates and apply as a directed foliar spray when grasses are actively growing. Use a surfactant to improve absorption on tough grasses. Overall, it is the best value choice for large-scale grass control in broadleaf plantings.
Pros:
- Excellent value concentrate
- Reliable grass control
- Safe on broadleaf plants
- Works on annual grasses
- Works on perennial grasses
- Systemic action
- Suits large areas
Cons:
- Toxic to desirable grasses
- Requires dilution and mixing
- Needs surfactant for tough grasses
11. Quizalofop-P-Ethyl Concentrate – Best Value Couch Grass Killer
Quizalofop-P-Ethyl Concentrate is the best value couch grass killer because it delivers reliable rhizome-killing control at an economical price. This concentrated formulation is a favourite for large beds with serious couch grass problems.
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The concentrated liquid is diluted with water and applied as a foliar spray, providing reliable couch grass control at low cost per treatment. It kills rhizomes systemically while remaining safe on broadleaf plants. Therefore, it offers dependable couch grass control at excellent value.
Dilute quizalofop concentrate according to label rates and apply as a foliar spray when couch grass has plenty of leaf surface. Reapply after six to eight weeks if regrowth appears. Overall, it is the best value choice for couch grass control in mixed plantings.
Pros:
- Excellent value concentrate
- Kills couch rhizomes
- Safe on broadleaf plants
- Systemic action
- Effective at low rates
- Suits large areas
- Reliable results
Cons:
- Toxic to desirable grasses
- Requires dilution and mixing
- May need repeat applications
12. Clethodim Concentrate – Best Value For Dense Grass
Clethodim Concentrate is the best value option for dense grass infestations because it delivers reliable control at an economical price. This concentrated formulation is a favourite for commercial growers and large properties.
The concentrated liquid is diluted with water and applied as a foliar spray, providing reliable control of tough perennial grasses at low cost per hectare. It is safe on a wide range of broadleaf crops and ornamentals. Therefore, it offers dependable grass control at excellent value.
Dilute clethodim concentrate according to label rates and apply with a crop oil concentrate for best absorption. Spray when grasses are actively growing and not drought-stressed. Overall, it is the best value choice for severe grass infestations in broadleaf plantings.
Pros:
- Excellent value concentrate
- Controls tough perennial grasses
- Safe on broadleaf crops
- Systemic action
- Suits large areas
- Rainfast quickly
- Widely used commercially
Cons:
- Toxic to desirable grasses
- Needs crop oil concentrate
- Requires dilution and mixing
13. Fenoxaprop-P-Ethyl Concentrate – Best Value Crabgrass Killer
Fenoxaprop-P-Ethyl Concentrate is the best value crabgrass killer because it delivers reliable annual grass control at an economical price. This concentrated formulation is a favourite for large lawns and beds where crabgrass is a recurring problem.
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The concentrated liquid is diluted with water and applied as a foliar spray, providing reliable crabgrass control at low cost per treatment. It is safe on broadleaf plants and works well in cool conditions. Therefore, it offers dependable crabgrass control at excellent value.
Dilute fenoxaprop concentrate according to label rates and apply when annual grasses are young and actively growing. Spray under cool conditions and avoid application during heat stress. Overall, it is the best value choice for crabgrass control in broadleaf plantings.
Pros:
- Excellent value concentrate
- Reliable crabgrass control
- Safe on broadleaf plants
- Works in cool conditions
- Fast-acting
- Suits large areas
- Easy to mix
Cons:
- Toxic to desirable grasses
- Limited on perennial grasses
- Requires young weeds
14. Fluazifop Granular – Best Granular Grass-Only Herbicide
Fluazifop Granular is the best granular grass-only herbicide because it is easy to apply around beds and borders without spray equipment. This granular formulation is a favourite for home gardeners who prefer simple application.
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The granules are scattered around grass-infested areas and watered in, releasing the active ingredient where grasses are growing. It is safe on broadleaf plants and requires no mixing or spraying equipment. Therefore, it offers convenient grass control with genuine broadleaf safety.
Apply fluazifop granules according to label rates around the base of grass weeds and water in thoroughly to activate. Avoid scattering granules directly onto desirable grass lawns. Overall, it is the best granular choice for simple grass control in broadleaf beds.
Pros:
- No spray equipment needed
- Simple to apply
- Safe on broadleaf plants
- Convenient for home gardens
- Effective on many grasses
- Lower drift risk
- Easy to store
Cons:
- Toxic to desirable grasses
- Requires watering in
- Slower than liquid formulations
15. Fluazifop Ready-to-Use Spray – Best Ready-Mixed Grass Killer
Fluazifop Ready-to-Use Spray is the best ready-mixed grass killer because it requires no dilution or mixing for quick, targeted application. This convenient formulation is a favourite for spot-treating grasses in small beds and containers.
- Kills weedy grasses without injuring ornamental plants
- For use in and around ornamentals, ground covers, evergreens, shrubs, shade trees, and non-bearing tree crops and vines
The pre-mixed spray is applied directly to grass foliage, providing reliable control without the need for measuring or mixing. It is safe on broadleaf plants and ideal for small areas and container plantings. Therefore, it offers convenient grass control with genuine broadleaf safety.
Apply fluazifop ready-to-use spray directly onto grass foliage when grasses are actively growing, shielding any desirable grasses nearby. Repeat after six weeks if regrowth appears. Overall, it is the best ready-mixed choice for spot grass control in small plantings.
Pros:
- No dilution needed
- Ready to spray immediately
- Safe on broadleaf plants
- Ideal for small areas
- Precise spot treatment
- Convenient storage
- Easy for beginners
Cons:
- Toxic to desirable grasses
- Higher cost per volume
- Limited for large areas
7 Essential Factors For Choosing Herbicide That Kills Grass But Not Broadleaf
Grass species: Different graminicides target different grasses, so identify the weed first. Fluazifop and quizalofop excel on couch grass, while fenoxaprop performs best on crabgrass and annual grasses.
Growth stage: Selective grass killers work best when grasses are young and actively growing. Mature or drought-stressed grasses absorb less chemical and may regrow after treatment.
Application timing: Apply when temperatures are moderate and rain is not forecast for at least six hours. Cool, calm conditions reduce evaporation and drift risk.
Surfactant use: Adding a non-ionic surfactant or crop oil concentrate improves absorption on tough grass species. Many labels require a surfactant for best results.
Desirable grass protection: These herbicides kill all grasses, including lawn grasses and ornamental grasses. Shield desirable grasses with cardboard or plastic during application.
Broadleaf safety: Confirm broadleaf safety for the specific plants in your bed, since some ornamentals and crops are more sensitive than others. Always read the product label for crop lists.
Legal and environmental limits: Some graminicides are restricted or banned in certain regions, and many carry buffer zone requirements near water. Check local regulations before purchase and use.
Frequently Asked Questions About Herbicide That Kills Grass But Not Broadleaf
1. What herbicide kills grass but not broadleaf plants?
Fluazifop-P-Butyl, sethoxydim, clethodim, quizalofop-P-ethyl, and fenoxaprop-P-ethyl are the main herbicides that kill grass but not broadleaf plants. These graminicides target grasses selectively without harming broadleaf species.
2. How do grass-only herbicides work?
Grass-only herbicides inhibit enzymes unique to grasses, blocking cell division and growth. Broadleaf plants lack these target enzymes, so they remain unaffected by the chemical.
3. Do these herbicides kill lawn grass?
Yes, these herbicides kill all grasses including lawn grasses and ornamental grasses. Shield or avoid desirable grasses during application, and never spray them directly.
4. How long does it take for grass to die?
Visible results usually appear within seven to fourteen days, with complete death taking three to four weeks. Systemic products kill rhizomes more slowly than contact herbicides but prevent regrowth.
5. Can I use these herbicides in vegetable gardens?
Some graminicides are registered for use in specific vegetable crops, including clethodim and tepraloxydim. Check the product label for approved crops and observe pre-harvest intervals.
6. Do I need a surfactant with grass-only herbicides?
Yes, most grass-only herbicides perform far better with a non-ionic surfactant or crop oil concentrate. Many labels require a surfactant, so always follow product instructions.
7. Are grass-only herbicides safe for the environment?
These herbicides are generally low-risk to mammals and birds but toxic to aquatic life. Follow buffer zone guidance, avoid spraying near water, and dispose of containers responsibly.
Conclusion
In conclusion, Fluazifop-P-Butyl is the best overall herbicide that kills grass but not broadleaf plants, combining reliable systemic control with genuine selectivity across annual and perennial grasses. Its ability to kill rhizomes while leaving broadleaf plants unharmed makes it the go-to choice for mixed beds and borders. Sethoxydim takes second place, offering faster visible results and excellent annual grass control.
For couch grass, Quizalofop-P-Ethyl and Fluazifop-P-Butyl deliver the most thorough results. For crabgrass, Fenoxaprop-P-Ethyl is the most targeted option. For dense or tough grass infestations, Clethodim provides the strongest control. For convenience, granular and ready-to-use formulations suit small gardens and spot treatments.
Each product offers different strengths in selectivity, speed, and application method. Choosing correctly depends on the grass species, the surrounding broadleaf plants, and the size of the area being treated.
Start clearing grass from your beds with these selective herbicides. Careful product choice, correct timing, and protection of desirable grasses will keep your broadleaf plantings healthy and free of invasive grass.