Ortho makes a number of weed killers, the most popular of which are its Weed B Gon products. Some of the Ortho weed killers are ready to use, while others are concentrated and need to be diluted. If you're going to use the concentrates, after diluting them you should spray weeds when they are small and actively growing. You should do this during daylight hours when the temperature is below 90 degrees. To stay ahead of the weeds, you should have to spray Ortho weed killer no more than twice a year.
Put on safety goggles or glasses and gloves to protect your eyes and skin from the concentrates.
Pour 2½ ounces of the Ortho Weed B Gon MAX Plus Crabgrass Control Concentrate into a garden sprayer tank. If you don't have a garden sprayer tank, use a large bucket. Other Ortho weed killers use the following amounts of concentrate: Weed B Gon MAX Weed Killer for Lawns: 2 ounces; Weed B Gon MAX for Southern Lawns: 1½ ounces for sensitive lawns, 2½ ounces for hardy lawns; Weed B Gon Chickweed, Clover and Oxalis Killer: 1 ounce.
Add one gallon of water to the sprayer tank or the bucket, regardless of the type or amount of concentrate.
Mix the water and weed killer concentrate well. If you're mixing in a bucket, use a stirring device. If you're using the garden sprayer, shake the container vigorously to mix the solution thoroughly.