Use 0.7 to 6.4 ounces of glyphosate per gallon of water

The ideal glyphosate mix depends on the target weeds and product concentration. For general weed control, use 0.7-2.5 oz per gallon (1-3% solution). Tougher weeds or high-concentration glyphosate (41%+) may require 3-6.4 oz per gallon. Always follow label instructions for safety and effectiveness.

Key Factors Affecting Glyphosate Mix Ratios

  • Weed type: Annual weeds need less (0.7-1.5 oz/gal); perennial or woody plants require more (3-6.4 oz/gal).
  • Glyphosate concentration:
    • 18% glyphosate: 1.5-3 oz/gal
    • 41% glyphosate: 0.7-1.5 oz/gal
    • 50%+ glyphosate: 0.5-1 oz/gal
  • Application method: Foliar spray (most common) vs. cut-stump treatment (undiluted for woody plants).
  • Water quality: Hard water may reduce effectiveness; add a surfactant if needed.

Glyphosate Mix Ratios by Use Case

Target Weeds Glyphosate Concentration Ounces per Gallon Notes
Annual grasses/broadleaf weeds 41% 0.7-1.5 oz Light infestations; reapply in 7-10 days if needed.
Perennial weeds (dandelions, thistle) 41% 2-3 oz Spray until leaves are wet but not dripping.
Woody plants (brush, vines) 41%+ 3-6.4 oz Use higher end for mature growth; add surfactant.
Cut-stump treatment Undiluted (50%+) N/A Apply directly to fresh cuts within 30 minutes.

Step-by-Step Mixing Instructions

  1. Calculate total spray needed: Measure area (1 gallon covers ~1,000 sq ft with fine spray).
  2. Fill sprayer halfway with water: Use clean, non-metallic container.
  3. Add glyphosate: Pour slowly while agitating to prevent settling.
  4. Add surfactant (if needed): 1 tsp per gallon improves adhesion.
  5. Top off with water: Leave 1-2% space for shaking.
  6. Mix thoroughly: Shake or stir for 30 seconds before use.

Safety and Effectiveness Tips

  • Avoid drift: Spray on calm days; use a shield near desirable plants.
  • Timing: Apply in early morning or late afternoon for best absorption.
  • Rainfastness: Requires 6+ hours of dry time post-application.
  • Storage: Mix only what you'll use; glyphosate degrades in diluted form.
  • PPE: Wear gloves, long sleeves, and eye protection during mixing/spraying.

Common Mistakes to Avoid

  • Overdiluting: Weak mixes reduce efficacy and may require reapplication.
  • Using metal containers: Glyphosate corrodes metal; use plastic or stainless steel.
  • Spraying in heat: Temperatures above 85°F (29°C) can reduce absorption.
  • Ignoring surfactant: Glyphosate alone may bead on waxy leaves.
  • Reusing mix: Glyphosate breaks down in water; discard unused solution.