Does Crossbow Kill Grass? Turf Safety and Mixing Guide

The Short Answer: Is Crossbow Safe for Turfgrass?

Crossbow Specialty Herbicide is a selective, systemic weed and brush killer. When applied at label-specified rates, it will not kill established, tolerant turfgrass species. The active ingredients—a blend of 2,4-D (butoxyethyl ester) and triclopyr (butoxyethyl ester)—are designed to target broadleaf weeds (dicots) and woody brush while leaving most common lawn grasses (monocots) unharmed.

However, the term 'selective' has strict biological and chemical limitations. Crossbow will severely damage, stunt, or outright kill certain warm-season grasses, particularly St. Augustine and Centipedegrass. Furthermore, applying the product at brush-killing concentrations, spraying during high-temperature inversions, or using improper surfactant loads will cause chemical burn and necrosis in otherwise tolerant grass species.

The Chemistry of Selectivity: Monocots vs. Dicots

To understand why Crossbow spares your lawn but destroys dandelions, clover, and blackberry brambles, you must look at plant metabolism. Both 2,4-D and triclopyr are synthetic auxins—plant growth regulators that mimic natural hormones. According to the Environmental Protection Agency (EPA), when broadleaf plants absorb these synthetic auxins, they trigger uncontrolled, unsustainable cell division. The plant's vascular tissue (phloem and xylem) collapses, cutting off water and nutrient transport, leading to rapid death.

Grasses survive this chemical assault due to three primary defense mechanisms:

• Enzymatic Degradation: Monocots possess specific enzymes (such as aryl-acyl-amidases) that rapidly metabolize and detoxify 2,4-D and triclopyr before they can cause systemic damage.
• Growth Point Protection: The meristematic tissue (growth points) of grasses is located at the base of the plant, near the soil line, shielded from direct foliar absorption.
• Vascular Structure: The parallel vein structure of grass leaves limits the translocation of the herbicide compared to the net-veined structure of broadleaf weeds.

For a deeper dive into how triclopyr specifically impacts plant biology and environmental breakdown, the National Pesticide Information Center (NPIC) provides comprehensive toxicological and environmental fate data.

Turfgrass Safety Matrix: Which Grasses Survive?

Not all lawns are created equal. Before mixing Crossbow, you must positively identify your turfgrass species. Applying this ester-based herbicide to sensitive grasses will result in severe chlorosis (yellowing), leaf curling, and eventual turf death.

Exact Mixing Rates for Lawn Applications

The most common reason homeowners accidentally kill their grass with Crossbow is by using 'brush and pasture' mixing rates on a residential lawn. The product label dictates vastly different concentrations depending on the target weed and the application method.

Broadcast Spraying (Entire Lawn)

For general broadleaf weed control (dandelion, clover, plantain) across a tolerant lawn, the target rate is 1 to 1.5 pints of Crossbow per acre.

• Per 1,000 sq. ft.: Mix 0.36 to 0.55 fluid ounces of Crossbow into 1.5 to 2 gallons of water.
• Per Acre: Mix 1 to 1.5 pints (16 to 24 fl oz) in 10 to 30 gallons of water.

Spot Treatment (Targeted Spraying)

For isolated patches of tough weeds or small woody brush (like blackberry or poison ivy) growing within the turf, use a handheld pump sprayer.

• Standard Weeds: Mix 1 to 1.33 fluid ounces of Crossbow per 1 gallon of water.
• Tough/Woody Brush: Mix up to 2 fluid ounces per 1 gallon of water (spray only the weed leaves, avoid drenching the surrounding grass soil).

Four Scenarios Where Crossbow Will Damage or Kill Grass

Even if you are spraying a tolerant grass like Tall Fescue or Bermudagrass, environmental and mechanical factors can turn a selective herbicide into a non-selective turf killer.

1. Ester Volatilization (Heat Drift): Crossbow uses butoxyethyl ester formulations. Esters are highly prone to volatilization (turning into a gas) when ambient temperatures exceed 85°F (29°C). This vapor drifts across the lawn, causing epinasty (twisting and cupping) and chemical burn on grass blades. Always spray in the early morning or late evening when temperatures are below 80°F.
2. Surfactant Burn: Crossbow does not contain a built-in surfactant. Adding a Non-Ionic Surfactant (NIS) at 0.25% v/v (roughly 1 teaspoon per gallon) is necessary to break the waxy cuticle of weeds like plantain or wild violet. However, NIS strips the protective wax off grass blades as well. If applied in direct, hot sunlight, the surfactant will cause rapid desiccation and brown spotting on the turf.
3. Tank Contamination: If you use a pump sprayer that previously held Glyphosate (Roundup) or an imidazolinone herbicide, trace residues will kill your grass. Crossbow will not clean the tank. Always use a dedicated tank for auxin herbicides, or triple-rinse with an ammonia-based tank cleaner before use.
4. Soil Root Uptake in Shallow Turf: While triclopyr has moderate soil activity, applying high concentrations (brush rates) to sandy soils can lead to root uptake by shallow-rooted grasses, causing delayed yellowing and root pruning weeks after application.

Cost and Sourcing: Brand Name vs. Generic Equivalents

Corteva Agriscience (formerly Dow AgroSciences) manufactures the brand-name Crossbow Specialty Herbicide. As of 2026, a 2.5-gallon jug of Crossbow typically retails between $140 and $170. Because a 2.5-gallon jug covers upwards of 5 acres at standard turf rates, the cost per 1,000 square feet is exceptionally low—roughly $0.06 to $0.08 per application.

For homeowners who do not want to store a 2.5-gallon jug of hazardous chemical, generic equivalents containing the exact same active ingredient ratio (Triclopyr 3 + 2,4-D Ester) are available in 1-quart or 1-gallon sizes under names like 'PastureGard HL' or 'Triclopyr 3 Select'. When purchasing generics, verify the active ingredient percentages on the label: you need exactly 34.4% Triclopyr and 34.4% 2,4-D to match Crossbow's efficacy.

Frequently Asked Questions

Will Crossbow kill crabgrass or nutsedge?
No. Crossbow is strictly a broadleaf and brush herbicide. It has zero efficacy on grassy weeds like crabgrass, goosegrass, or sedges like yellow nutsedge. For those, you need a specific graminicide (e.g., Quinclorac or Fluazifop) or a sedge-specific product like Sulfentrazone. The Texas A&M Aggie Turfgrass Program offers excellent identification guides for differentiating broadleaves from grassy weeds.

How long does it take for Crossbow to work?
Susceptible broadleaf weeds will show signs of epinasty (leaf curling and stem twisting) within 24 to 48 hours. Complete necrosis and root death typically take 10 to 14 days, depending on soil moisture and temperature. Do not reapply if you do not see immediate results; the systemic translocation takes time.

Can I seed my lawn immediately after spraying Crossbow?
No. Both 2,4-D and triclopyr leave active residues in the soil and on decaying plant matter. You must wait at least 3 to 4 weeks after application before overseeding or laying new sod, otherwise, the pre-emergent and early post-emergent activity will stunt or kill the new grass seedlings.