Larry from St. Joseph, Mo writes
Any post-emergent herbicide such as Southern Ag Lawn Weed Killer with Trimec or any 2,4-D product should be used only on established turfgrass. That means that if you have just reseeded, you need to wait until the new grass has been mowed at least twice before applying a post-emergent herbicide.
Answer last updated on: 10/09/2019