Scotts Halts Crabgrass & Grassy Weed Preventer prevents the germination of listed lawn weeds so you can enjoy your lawn. In early spring, apply these weed preventer granules when lawn is dry to prevent the germination of crabgrass, foxtail, spurge, barnyardgrass, fall panicum, goosegrass and oxalis all season long (for goosegrass control, repeat application in 8 weeks). Apply in the fall (August-October) to prevent moss (except in California), or to prevent the germination of Poa annua, henbit, corn speedwell, and chickweed. Scotts Halts Crabgrass & Grassy Weed Preventer is for use on all lawns and grass types (with the exception of Dichondra or Bentgrass lawns). Rain, snow, or freezing weather after application will not affect the performance of this product. It's a great lawn weed control option for homeowners, lawn enthusiasts, and groundskeepers. Please note, this weed and crabgrass killer for lawns controls crabgrass in its early stages of growth. It does not control mature crabgrass and other existing weeds. This bundle includes two 10.06 lb. bags of Scotts Halts Crabgrass & Grassy Weed Preventer, covering a total of 10,000 sq. ft.