I live in where I have to fertilize my lawn and put down insecticides often or have the home owners association after me. I wish I didn't have St. Augustine grass, but where I live the houses have to have them and I agree. The amount of money, water, time spend on the lawn care is horrible. During the summer I sometimes have to mow the lawn twice in a week.
Anyway I decided just to fertilize my frontyard as I don't want the puppy to be off a schedule and not understand that i have to grab the leash for it to go potty. I spoke to other people here and they told me that when they fertilize, they don't let the dog use the yard for 2 or 3 days.