For the most part, if you are handling your plants around the warm season, then you should use the 10-10-10 fertilizer about four times per year or so.
You can start the process when you first see them growing, just remember that you may need to dilute the formula quite a bit during this time to make sure that you don’t end up overdosing the lawn. After such you can add new doses at around a 30-day interval and just wing it for the rest of the process.