Designed to help prevent the growth of 52 different weeds and grasses. Ready to use Casoron Granules are recommended for sprinkling around established ornamental trees and shrubs fruit trees nut trees and berry plant's The granules help provide season long control of annual grassy and broadleaf weeds and certain perennial weeds. For Annual Weeds: Apply in early spring before weeds emerge or after removing weeds. For Perennial Weeds: For best control, apply after a killing frost from late fall to early winter.