2,4-D Amine Mix Ratio and Application Guide

2,4-D amine (2,4-Dichlorophenoxyacetic acid, amine salt formulation) is a selective broadleaf herbicide concentrate that is one of the most widely used active ingredients in residential lawn weed control. The concentrate formulation is cost-effective for treating large lawn areas and allows more control over the application rate than pre-mixed ready-to-use products. Using the correct mix ratio is essential, over-concentration causes turf injury and increases environmental exposure without improving weed control.

What 2,4-D Amine Controls

2,4-D is a systemic, selective broadleaf herbicide. It is absorbed through weed foliage and translocated to the growing points and root system, causing uncontrolled, distorted growth that leads to plant death in susceptible species. It is selective in that established turfgrasses, most cool-season and some warm-season species, are tolerant of 2,4-D at normal application rates.

Weeds effectively controlled by 2,4-D:

  • Dandelion
  • Plantain (broadleaf and buckhorn)
  • Chickweed (common and mouse-ear)
  • Oxalis (wood sorrel)
  • Henbit
  • Wild mustard
  • Curly dock

Weeds with moderate resistance to 2,4-D alone (benefit from combination products):

  • White clover (requires mecoprop or dicamba in combination)
  • Ground ivy (requires triclopyr in combination)
  • Wild violet (requires triclopyr in combination)

Weeds not controlled by 2,4-D:

  • Any grassy weed (crabgrass, annual bluegrass, goosegrass)
  • Nutsedge and other sedges
  • Horsetail

Grass Types Safe for 2,4-D Application

Compatible with 2,4-D at labeled rates:

  • Kentucky bluegrass
  • Tall fescue
  • Fine fescue
  • Perennial ryegrass
  • Bermuda grass (use caution at high temperatures)
  • Zoysia grass (use caution, follow label)

Not compatible with 2,4-D:

  • St. Augustine grass: 2,4-D causes significant injury. Do not use.
  • Centipede grass: Sensitive. Do not use 2,4-D on Centipede.
  • Dichondra lawns: Dichondra is a broadleaf plant that will be killed by 2,4-D.

Always verify your grass type before purchasing or applying any 2,4-D product. The product label lists compatible grass types specifically.

Standard Mix Ratio for 2,4-D Amine Concentrate

2,4-D amine concentrate products vary in their active ingredient concentration. The two most common consumer products are:

  • Ortho Weed B Gon Concentrate (5.1% 2,4-D amine): 5 tablespoons per gallon of water for spot treatment; 2.5 ounces per gallon of water for broadcast application. Always check the label for your specific lot.
  • Hi-Yield 2,4-D Selective Weed Killer (46.8% 2,4-D amine): Approximately 3/4 ounce (1.5 tablespoons) per gallon of water for broadcast application on lawns.

General rule: The correct mix ratio is always on the product label and is specific to the active ingredient concentration of that product. Do not transfer mix ratios between products with different concentrations.

Standard Mix Ratio Calculation

To calculate the correct rate for any 2,4-D concentrate:

  1. Find the active ingredient (AI) percentage on the product label
  2. Determine the labeled broadcast rate in pounds of active ingredient per acre (typically 0.5 to 2 pounds AI per acre for lawn use)
  3. Calculate: For 1,000 square feet at 1 pound AI per acre, the rate is approximately 0.023 pounds AI per 1,000 sq ft

For most homeowner applications, use the specific rate table on the product label rather than calculating from first principles. The label table matches the product’s specific concentration to practical measures (teaspoons, tablespoons, or ounces per gallon of spray).

Application Method

Equipment

Apply 2,4-D amine concentrate using:

  • Pump-up sprayer (1 to 2 gallon): Best for spot treatment of isolated weed patches
  • Hose-end sprayer: Convenient for broadcast treatment of larger lawns. Check that the sprayer dial setting delivers the correct dilution rate.
  • Backpack sprayer: Best for large properties or commercial-scale applications

Mix only the amount you need for a single application. Do not store mixed 2,4-D solution.

Application Steps

  1. Fill the sprayer partially with water
  2. Add the measured amount of 2,4-D concentrate
  3. Add a non-ionic surfactant at the label rate if recommended (surfactant improves leaf adhesion, particularly on waxy-leafed weeds)
  4. Fill to the final volume with water and agitate gently
  5. Apply to actively growing weed foliage using an even, overlapping spray pattern
  6. Do not apply when wind exceeds 10 mph, drift onto ornamental plants, vegetables, and adjacent properties causes damage
  7. Do not apply when temperatures exceed 85 to 90 degrees Fahrenheit

After Application

  • Do not mow for three to four days after application
  • Do not water for 24 hours after application
  • Observe the product-specific re-entry interval for people and pets

Environmental and Safety Notes

Proximity to water: 2,4-D is mobile in soil and has the potential to reach groundwater and surface water. Do not apply within 15 feet of water features, storm drains, or drainage channels. Do not apply before heavy rain events.

Drift risk: 2,4-D amine is less volatile than the ester formulation of 2,4-D, making it a better choice near ornamental plantings and in warm weather. The amine salt formulation is standard for consumer lawn care use.

Ornamental plant sensitivity: Tomatoes, grapes, roses, and many ornamental plants are highly sensitive to 2,4-D. Even small amounts of drift can cause characteristic distorted, epinastic (downward-curling) leaf symptoms. Apply on calm days and maintain buffer distance from sensitive plants.

Personal protective equipment: Wear chemical-resistant gloves, eye protection, and avoid skin contact during mixing and application. Wash hands and any exposed skin after application. Store in original container with lid secured, away from children and pets.

Related Guides

For the full timing and application process for broadleaf herbicide treatment, see when to apply weed and feed to your lawn. For pet safety and re-entry intervals, see best pet-safe weed killers for lawns.