need portion/how often a gardenia house plant needs feeding of JG flower fertilizer 5-10-5

I would not recommend on indoor house plant. Meant for outside flowers and veggies etc. All quick release. I would go with something with organics. Such as Jonathan Green Rose and Flower 5-8-1. A more premium food of organics, and natural ingredients. Slow release is gentle feeding. Micro mutrient package has all essential elements.