|How does weed and feed work? Does it kill weeds and allow the grass to grow?|
I apologize for this delayed reply to your gardening question and hope it is still helpful to you.
Weed and feed simply means that the product contains fertilizer and some type of herbicide. The idea is that the fertilizer feeds the grass and the herbicide while toxic to weeds will not harm the grass. If it is a preemergence herbicide it will prevent weed seeds from coming up but not control existing weeds. If it is a post emergence herbicide it will control existing weeds but not prevent weed seeds from coming up. Now as usual, the devil is in the details. The best time to fertilize is usually not the optimum time to prevent weeds. The best time to start fertilizing warm season grasses in the spring is after you have mowed twice. By then weeds have already germinated. In fall weed prevention also comes prior to fertilizing. If you need to use a herbicide it is best to first have the weeds identified so you can choose the proper product for optimum control and also get the proper timing for application. Then apply it separately from your lawn fertilization.
Keep in mind also that Centipede doesn't like to be fertilized much at all.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!