Things You'll Need
Shoes that repel moisture
Clean bottle or other container
St. Augustine grass is a perennial grass that is commonly used for lawns and pastures. It grows well in coastal areas because of the moisture and mild winters, keeping its green color when the mercury dips. St. Augustine grass is prone to weeds like crabgrass and dandelions. Atrazine is an herbicide used to control weeds. It's one of the few St. Augustine will tolerate. The liquid form is highly regulated by the EPA, and only trained people are allowed to disperse it. However, powder forms are available for residential use.
Put on protective clothing such as long pants, a long sleeved shirt and socks. The atrazine product label also recommends you wear latex gloves and footwear that repels water as added protection against the chemical.
Mix water with the herbicide in a clean container such as a bottle. If you're treating 500 square feet of St. Augustine grass, mix 1.5 tbsp. of atrazine with 1 gallon of water. For one acre, mix 2 qt. with 40 to 80 gallons of water.
Stir the solution with a stick to agitate it. Work on it until the powder or liquid is dissolved in the water.
Seal the container. Shake it if you think the solution is settling.
Spray the atrazine on your lawn, using it only in areas that are protected from wells, sinkholes and bodies of water. There should be at least a 100 foot buffer zone. Focus the spray on the foliage of weeds. Coat each problem area once. Do not overlay the spraying because you don't want to apply too much of the herbicide.
Run water over your gloves to rinse off the residue. Remove your clothing and footwear. Wash them in hot water with detergent, separately from the rest of your laundry.
Rinse out the containers. Throw away the bottles you don't plan to use again for an atrazine application. Never dump the water onto the ground.
For best results, apply atrazine to St. Augustinegrass in early spring or during dormant periods when the weeds are young.
Never spray atrazine on windy days because it will drift onto other plants.