Quinclorac is a selective grass herbicide that can be sprayed on switchgrass plantings to control grasses such as foxtail and crabgrass. Each 1# bottle will cover 1 acre. This is a dry product that should be mixed with a minimum of 20 gallons of water per acre and is best used with a agitator in sprayer tank to keep product from settling in tank. For best results it is important that quinclorac be applied when foxtail/crabgrass is very young. (less than 8″). As these grasses mature, quinclorac will become much less effective on their control.