This pre-emergent weed stopper can be applied in early spring and late fall to prohibit growth of the following weeds: Chickweed, Henbit, Spurge, Crabgrass, Dallisgrass and more. Safe to use around ornamental plants like roses, and should be applied after all weeds have been removed from the beds.  Broadcast the Weed Stopper at a rate of 1 pound per 200-250 square feet (a bed of 18-24 roses). Broadcast over mulch or directly on the soil if it is a newly prepared bed, adding mulch afterwards.