but you don't -- is a pre-emergent herbicide most often associated with a product called Dimension. But it's also the active ingredient in Preen's Crabgrass Control product. Dithiopyr works by ...

The crabgrass killer is Dimension. And its “extra strength” dose means it will keep your lawn crabgrass-free longer than other pre-emergents. Dimension kills crabgrass for a short period of ...

Now is the time to apply the first dose of a pre-emergent herbicide to prevent germination of the annual weeds.