Jonathan Green Lawn Weed Control contains Trimec, a herbicide that suppresses broadleaf weeds when they are actively growing. Lawn Weed Control kills hard to control weeds such as dandelions, clover, henbit, oxalis, wild onion and over 200 other weeds. For optimal results spread this product on a moist lawn so the weed control granules stick to the plant leaves. Use Lawn Weed Control on all types of cool and warm-season grasses, when you want to kill weeds but have no intention of seeding or fertilizing. For particularly difficult weeds, make a second application of Lawn Weed Control 30 days after the first application.