A high-quality Atrazine product will be effective when mixed at a rate of 4 1/3 ounces per gallon of water. The resulting mix is enough to treat 500 square feet of lawn safely. When applied to an Atrazine-safe grass, the herbicide will work to kill broadleaf weeds and pest grasses without harming your lawn.
Always mix Atrazine according to manufacturer specifications and apply the resulting mixture to the appropriate square footage. If used incorrectly, or at too high of a concentration, Atrazine can harm desirable grasses.
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Atrazine Mixing Instructions for Home Use
When using a 4% Atrazine mix, such as Southern Ag Atrazine, mix 4.33 ounces of Atrazine per gallon of water. To ensure the Atrazine mixes completely with the water, pour the Atrazine into the container first, followed by the water. One gallon of Atrazine and water mix is enough to kill weeds in a 500 square-foot area without harming your grass.
- Mix 4.33 ounces of Atrazine per gallon of water.
- When mixing in a container, pour Atrazine first, followed by water for best results.
- Apply the mixture to 500 square feet of lawn.
- Do not increase Atrazine content per gallon of water.
- Do not apply Atrazine at higher rates than those listed on the product label.
- Do not mix Atrazine with other chemicals.
If you increase the concentration of your Atrazine mix, or if you apply the mix at a greater rate than 1 gallon per 500 square feet, you risk damaging your turfgrass. At high levels, Atrazine can become toxic to the lawn you want to protect. Atrazine should never be mixed with other chemicals, additives, or herbicides. Because Atrazine must penetrate the soil to be effective (it attacks weeds through the roots) surfactants should never be added to Atrazine.
How To Apply Atrazine To Your Lawn
Atrazine is best applied to your lawn with a pump sprayer or backpack sprayer. Alternatively, use an adjustable hose-end sprayer with metering controls that allows you to mix 4.33 ounces of Atrazine per gallon. Apply on a day with little to no wind, when the temperature is between 65–90℉ (18–32℃).
- Use a pump sprayer or backpack sprayer to spread your Atrazine mix.
- Alternatively, use a hose-end sprayer system with metering controls to apply Atrazine.
- Spray Atrazine on a day with low or no wind.
- Daytime temperatures must be 65–90℉ (18–32℃) for best results.
If Atrazine is applied during windy conditions, the herbicide may be carried onto trees, garden plants, or neighboring property where it can kill plants. Remember, Atrazine attacks broadleaf plants (trees, shrubs, weeds, vegetable plants, and ornamentals) as well as most grasses. It must be used carefully. Additionally, Atrazine is not effective outside the temperature range of 65–90℉ (18–32℃). It will give little to no result if applied during excessively hot or cool weather.
Is Atrazine Safe For Your Grass?
Atrazine is only safe for use on St. Augustine, Centipede Grass, and Zoysia lawns. Other turfgrasses will be killed by the herbicide.
- Use Atrazine On: St. Augustine, Centipede Grass, and Zoysia lawns.
- Do Not Use Atrazine On: Bermuda Grass, Buffalo Grass, Fescue, Ryegrass, Bentgrass, Kentucky Bluegrass, and Cool-Season Grass Mixes.
Review manufacturer labeling to make sure your grass type is safe for Atrazine exposure before use.
Is Atrazine Effective?
When mixed correctly, Atrazine is a very effective weed killer, capable of attacking grassy and broadleaf weeds while leaving specific turf grasses unharmed.
- Attacks broadleaf weeds and many invasive types of grasses.
- Is a selective weed killer, meaning it will not harm specific turf grasses (St. Augustine,
- Centipede, and Zoysia).
- Kills existing weeds in 14–21 days.
- Works as pre-emergent, killing sprouting seeds underground for up to 6 weeks.
Atrazine is unique because it is both a post-emergent and pre-emergent herbicide. It is capable of killing both established annual weeds and stopping new weeds from sprouting. This is because Atrazine enters the soil and remains there for several weeks. It will stomp out the clover in your yard and kill new seeds just as they try to germinate.
How Many Ounces of Atrazine Per Gallon of Water?
The ideal mix for 4% Atrazine solutions is 4.33 ounces of Atrazine for 1 gallon of water. This amount, when applied with a pump, backpack, or hose-end sprayer, can treat 500 square feet of lawn. You should always follow product label guidelines for Atrazine mixing, safety, and application instructions.
Once applied, Atrazine will go to work, attacking weeds through the root and killing weed seeds underground. Within 14–21 days, the existing weeds in your yard will be dead. Meanwhile, weed seeds will be killed as they germinate for up to 6 weeks. Best of all, your lawn will be left to flourish unharmed.