What affect will rain have on a pre-emergent treatment?
How will rain affect the pre-emergent that was applied to my lawn?
That’s a good question. A lot of people think rain will wash away our products and make them ineffective, but this is simply not true. Actually, rain makes our lawn treatments work much better.
In order for a pre-emergent to effectively keep weeds from growing in your lawn, it must be incorporated into the soil. That is exactly what rain does. It pushes the pre-emergent down into the soil to make it work. Once the pre-emergent has been incorporated into the soil it will prevent weeds such as crabgrass from growing in your lawn. Most pre-emergent product labels actually say the product needs to be watered in within a few days after application.
How does rain affect the weed killer?
In most cases, rain helps weed killer products work better too. When it rains something inside the plant is triggered to make the plant take in the water that is available. When that happens and our weed killer has been applied to the weed, the plant will ingest the herbicide and we will control that weed. We use a surfactant with all our weed control products to help them stick to the leaf of the plant better. As long as our product has 3 to 4 hours to sit on the weeds before it rains, it will still be effective.