Spring's arrival brings lush green grass, and unwanted weeds in your lawn. Applying Preen Lawn Weed Control to your lawn when weeds are actively growing kills them without harming your lawn. To reduce the risk of drift and wash-off, apply Preen on a calm day when rain is not expected for at least 24 hours. Protect yourself when handling the product by wearing long sleeves, pants, eye protection, and chemical-resistant gloves and shoes.

Single dandelion
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Preen treats lawn weeds without back-breaking pulling.

Step 1

Mow the area 24 to 48 hours before you intend to treat it.

Step 2

Measure the length and width of the section of lawn you wish to treat. Multiply length times width to get total area in square feet. If the area is an irregular shape, break it into square or rectangular sections, then add those areas to get total square feet to be treated.

Step 3

Water thoroughly the area to be treated the evening before you intent to apply Preen. You won't be able to water again until 48 hours after treatment. This will keep the lawn hydrated.

Step 4

Calculate how many pounds of Preen Lawn Weed Control you need to treat your total square footage. Each 1,000 square feet of lawn requires 2 pounds of herbicide. If your total area is 1,500 square feet, you need 3.5 pounds of herbicide.

Step 5

Place a container on the bathroom scale. Weigh out the amount of Preen you calculated to treat the area. Pour the measured amount into the spreader. Do not reuse the container for eating, drink or watering plants. Preen is toxic to humans, and residue will damage plants.

Step 6

Set the spreader to the recommended setting for your type and brand of spreader. Recommended settings are found on the Preen Lawn Weed Control label.

Step 7

Apply Preen early in the morning when grass is covered with dew. If dew is absent, lightly water the area to be treated with a garden hose. Moisture is needed to make Preen stick to weeds and reduce the chance of drift.

Step 8

Reduce the chance of overspraying Preen onto sidewalks and other hard surfaces when using a broadcast spreader by starting on the perimeter and walking around the area in a circular motion toward the center. For drop spreaders, apply to each end of the area first, then walk back-and-forth along the length of the lawn. Work your way from one side of the lawn to the other. Shut off the spreader when making turns at each end so you don't over-treat those areas.

Step 9

Sweep any stray granules from driveways and other hard surfaces onto the lawn.

Step 10

Water lawn thoroughly after 48 hours.