For best results, we recommend using Roundup® Weed & Grass Killer products on dry, warm, wind-free days. But if it’s about to rain, fear not — all of our products should dry and become waterproof within 30 minutes to two hours — some even faster.
A wind- and rain-free day above 60° F helps prevent drift and helps speed up drying of Roundup® Weed & Grass Killer products.
Weeds love to sprout after it rains, which is why waiting for dry conditions is ideal. Waiting for rain-free days also ensures that Mother Nature won't wash away any of the product before it goes to work on the weed