Whatever you do, you want a low nitrogen fertilizer or they will put on lots of lush green leaves and few peppers. I prefer 5-10-10 when I plant and then nothing till they flower. Then a very light dose of a high phosphorus/low nitrogen will keep them going till fall. Most flowering plants will be better if they don't have too much nitrogen. Leafy crops or grasses or foliage plants in the flower garden benefit from higher nitrogen fertilizers.