Wow, you really jumped the gun. Feeding the lawn before it greens up and starts growing is a waste and also illegal…applying lawn food in NYS is illegal before 4/1. Most of the food will be washed away and into the waterways with spring rain…which is why it is illegal. The crabgrass preventer won’t work because the chemical will be broken down and long gone by the time the crabgrass seeds begin to sprout. You were about a month early HERE’S A LINK to help you understand how to time your crabgrass preventer application. Yes, it will need to be redone at the proper time.