I use a granular slow release fertilizer. Won't say the ratios however. Keeps them blooming large flowers and their shape stays compact. Too much nitrogen and it will take away from their form. They will get leggy. Also we pinch the old blooms off every 2 weeks.
Everyday you wake up you have been given 24 hours. What you do with those hours determines how rich you will become. The rich work the hours you don't see.
Great Book: "Think and Grow Rich"