Jonathan Green Season-Long Weed Preventer for lawns and landscapes contains Dimension®, a clear and odorless chemical that kills and prevents crabgrass both before and after it germinates – up to the 3rd leaf stage. At maturity crabgrass is a 7-leaf plant. Dimension® also stops more than 30 other grassy and broadleaf weeds from invading the lawn and garden beds if applied before the weeds germinate. The weed control lasts for the entire growing season. Crabgrass seeds germinate over many months, so if crabgrass has been a persistent problem, apply this product again in late-May to mid-June to stop these late germinating seeds from establishing. The easy to spread granules are also great to use to prevent weeds from growing around more than 100+ ornamental plants, all of which are listed on the product label.