Why Centipede Grass Is Highly Sensitive to Herbicides Like Metsulfuron

Centipede grass (Eremochloa ophiuroides) is a popular warm-season turfgrass known for its low maintenance and shallow root system—but these very traits also make it more vulnerable to herbicide injury, especially from sulfonylurea compounds like metsulfuron-methyl.

Unlike more tolerant species such as Bermuda or Zoysia grass, centipede grass:

• Has lower nitrogen and water needs, meaning any disruption to its physiological balance can trigger rapid stress symptoms;
• Possesses thin cuticles and a slower metabolism, reducing its ability to detoxify residual herbicide in the leaf or root system;
• Shows narrow tolerance thresholds, particularly when exposed to systemic herbicides with long soil activity.

In field observations, centipede lawns sprayed with metsulfuron under suboptimal conditions—such as high heat, drought stress, or after recent fertilization—are much more likely to exhibit chlorosis, growth suppression, and even patchy die-off.

Therefore, understanding this grass species’ physiology is key before introducing any chemical control. Metsulfuron should be viewed as a tool for experienced applicators, not a default solution for everyday lawn care.

Safe Application Guidelines: How to Use Metsulfuron-methyl Without Damaging Centipede Lawns

Applying metsulfuron-methyl to centipede grass requires precision, restraint, and favorable conditions. While this herbicide can control many troublesome broadleaf weeds, even slight missteps can result in turf injury. Follow these best practices to minimize risk:

1. Use the Lowest Effective Rate

• Apply 0.1–0.25 oz per acre (2.8–7 grams/ha) of active ingredient.
• For most ready-mix products (e.g., 60% WDG), this equates to 0.17–0.42 oz of product per acre.
• Never exceed labeled rates, especially on centipede.

2. Timing Is Crucial

• Apply during moderate temperatures (ideally 65–85°F / 18–29°C).
• Avoid applications before or after heavy rainfall, or during drought stress.
• Best applied when grass is actively growing but not newly seeded or recently fertilized.

3. Watering & Mowing Guidelines

• Do not mow 2 days before or after application, to reduce turf stress and herbicide absorption.
• Irrigate lightly 12–24 hours after spraying if no rain occurs, helping move product into the root zone without pooling.

4. Avoid Certain Adjuvants or Mixtures

• Do not use oil-based surfactants or methylated seed oils (MSOs)—these increase absorption and raise phytotoxicity risk.
• Use only non-ionic surfactants (NIS) at 0.25–0.5% v/v if necessary.
• Avoid mixing with other herbicides unless turf safety has been tested.

5. Calibrate Equipment Accurately

• Ensure uniform application with low-pressure flat fan nozzles.
• Prevent overlap or double coverage, especially on lawn edges or slopes.

Effective Weed Control: What Metsulfuron-methyl Targets on Centipede Lawns

One of the main reasons metsulfuron-methyl is still considered by turf managers—despite the risks on centipede grass—is its broad-spectrum control of persistent broadleaf weeds, especially those that resist other selective herbicides. When used properly, it provides long-lasting suppression with minimal regrowth.

Top Weeds Controlled by Metsulfuron on Centipede Grass:

Weed Name	Control Level	Notes
Clover (Trifolium spp.)	High	Excellent control with visible results in 7–10 days
Spurge (Euphorbia spp.)	High	Often controlled with one treatment
Dollarweed (Hydrocotyle spp.)	Medium–High	May require sequential application
Plantain (Plantago spp.)	High	Best when treated at rosette stage
Chickweed (Stellaria spp.)	Medium	Effective when young; older weeds less responsive
Dandelion (Taraxacum spp.)	High	Reliable knockdown with proper timing

Additional Weed Types:

• Henbit
• Wild garlic
• Thistle
• Curly dock
• Oxalis

While metsulfuron is not suitable for grassy weed control, it complements programs targeting hard-to-kill dicot weeds—especially in warm-season lawns where few alternatives are registered.

Pro Tip: Weeds should be actively growing at time of application. Drought-stressed or over-mature weeds are harder to kill and more likely to require a follow-up treatment.

What If You See Turf Injury? Recognizing and Responding to Metsulfuron Damage

Despite your best efforts, centipede grass may still show signs of phytotoxicity after metsulfuron application—especially if environmental conditions, surfactants, or dosage were less than ideal. It’s essential to act quickly and correct course before long-term damage occurs.

Common Symptoms of Metsulfuron Injury on Centipede Grass:

• Chlorosis (yellowing) in the leaf tips or patches across the lawn
• Stunted growth or lack of recovery following mowing
• Thinning turf or reduced density in treated zones
• Delayed green-up during early spring if applied late in the prior season

What To Do If Injury Occurs:

1. Irrigate Immediately: Apply 0.5–1 inch of water to help leach excess herbicide beyond the root zone.
2. Cease Mowing & Fertilizing: Give the turf time to recover before introducing additional stress.
3. Apply Light Nitrogen: After 10–14 days, a low-rate nitrogen boost (0.25 lb N/1000 sq ft) can help stimulate regrowth.
4. Avoid Repeat Applications: Do not reapply metsulfuron until full recovery is visible.
5. Monitor for Regrowth: Centipede grass can recover over time, but full canopy closure may take several weeks depending on damage severity.

Caution: Turf under stress from drought, disease, or previous chemical applications is significantly more likely to suffer lasting injury.

Safer Alternatives: Herbicide Options Beyond Metsulfuron for Centipede Lawns

If you’re concerned about the potential for injury, or you’ve had a bad experience using metsulfuron-methyl on centipede grass, there are safer alternatives available—products that offer good weed control while posing less risk to sensitive turf.

Alternative Herbicides Recommended for Centipede Grass:

Active Ingredient(s)	Use Case
Atrazine	Broadleaf + grassy weed control, safe when dormant
Halosulfuron-methyl	Effective on nutsedge, low injury potential
Mesotrione	Pre- and post-emergent control of broadleaf weeds
2,4-D + Dicamba + MCPA	Spot treatment for broadleaf weeds in southern turf
Thiencarbazone + Iodosulfuron	Designed for warm-season grasses like centipede

These products typically have a wider safety margin when applied under labeled conditions and can be part of a rotating weed management plan to reduce resistance pressure.

Non-Chemical Approaches to Weed Management:

• Frequent mowing at correct height (1.5–2.0 inches) discourages weed establishment
• Proper fertilization and irrigation to promote dense turf cover
• Hand-pulling of isolated broadleaf weeds before seed set
• Spot spraying rather than blanket applications

Ultimately, the best approach may be to reserve metsulfuron for specific problem zones, and use less aggressive tools for general weed management. This keeps your lawn healthy while extending the life and performance of all herbicides in your program.

Final Verdict: Should You Use Metsulfuron on Centipede Grass?

Metsulfuron-methyl is undeniably a powerful broadleaf herbicide, offering long residual control and broad-spectrum efficacy—but when it comes to centipede grass, its use is a calculated risk.

When Metsulfuron Might Be Justified:

• You’re dealing with persistent weeds (e.g., wild garlic, dollarweed, oxalis) that haven’t responded to safer herbicides.
• You have experience applying sulfonylurea herbicides and understand the sensitivity window of centipede turf.
• You plan to spot treat problem areas rather than apply broadly.
• Environmental conditions are optimal—mild weather, moist soil, no recent fertilization.

When You Should Avoid It:

• Your centipede lawn is already under stress (drought, pest, heat).
• You lack experience with precise mixing or application techniques.
• You expect to apply during summer peak or after recent feeding.
• You’re looking for a blanket application for a general weed problem.

Bottom Line: If you’re unsure, don’t guess. Test first on a small area, monitor results for 2–3 weeks, and then decide whether metsulfuron fits your lawn care plan.

Metsulfuron can be part of a centipede grass strategy—but only for the right lawn, the right conditions, and the right user.