Preen One Lawncare: It's time to rethink your lawncare routine. Preen One delivers three essential lawn treatments in one. This one-step application for spring lawncare feeds the lawn for 8 weeks, kills over 250 lawn weeds commonly found in home lawns including dandelions, chickweed, thistle, clover and more, on contact. It prevents crabgrass seeds from sprouting and, unlike traditional crabgrass prevention products, also kills crabgrass seedlings up to 4 weeks after germination. For a complete list of weeds, see the product label. Choose the one that's only one so you can spend more time enjoying your lawn and less time working on it.