Plants should dry within one hour and the weedkiller

will be able to withstand rain at that time. Apply when weeds are seen and actively growing. Rain or watering 1 hour after application will not wash away effectiveness.

How long until Ortho Weed B Gon is rainproof?

Apply when weeds are actively growing. Rainproof 6 hours after application. Spray when temperature is below 90 degrees. Spray when air is calm to avoid drift to desirable plants.

How long does weed killer take to dry before rain?

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 rainfast within 30 minutes to 3 hours — some even faster.