Scotts WeedEx Prevent with Halts prevents the germination of listed lawn weeds so you can enjoy your lawn and stop weeds before they start. 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 WeedEx Prevent with Halts 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 DIY homeowners, lawn enthusiasts, and groundskeepers that provides a lawn protection and lawn maintenance product for their spring lawn care routine. Please note, this pre-emergent weed and crabgrass killer for lawns controls crabgrass in its early stages of growth. It does not control mature crabgrass and other existing weeds. One 10.06 lb. bag of Scotts WeedEx Prevent with Halts covers 5,000 sq. ft.