Scotts WeedEX Prevent with Halts, 10.06 lbs. is designed to keep your lawn beautiful all season long by preventing crabgrass and other troublesome weeds. Apply it in early spring when the lawn is dry to stop the germination of crabgrass, foxtail, spurge, barnyardgrass, fall panicum, and oxalis. In the fall, between August and October, it helps prevent moss (except in California) and the germination of Poa annua, henbit, corn speedwell, and chickweed. For results, use a spreader as by the manufacturer: setting 2 for Scotts broadcast/rotary spreaders, 4 for Scotts drop spreaders, and 3 for ScottsWizz. Weather conditions like rain, snow, or zing temperatures after application will not affect its performance. Note that this product controls crabgrass only in its early growth stages and does not affect mature crabgrass or existing weeds. Model Number: