It depends on where you live and what type of spring weather you get. I'm in Ohio and generally we don't have to fertilize in Mid to late April, depending on the last frost. We usually don't have to start watering until after we plant flowers and then on a regular basis after our spring showers/rains slow down. Good Luck. You might contact your local extension office or agricultural department and they could probably give you a more detailed schedule to follow.

Preferably after all danger of frosts plus a couple of weeks.