maybe start them on some bloomin nutes higher in the P. on all plant ferts there is a label an on that label there should be a series of 3 numbers wit hyphens between them such as (25-20-15_ each number represents each sectin of netes one bein the N, bein nitrates, P bein phosphates i beleive correct me if wrong anyone... and the other is k bein potash. the N-P-K ratio. find one higher in the P ratio. but start it on say half the dose once then next time 3/4 then finally a full dose by the third feeding wheenin them into the new nutes not to burn any roots.
this is wat i did for mine an they on their full dose the last feeding and they doin magnificent now. hence my disclaimer here in case u decide to follow my exact plan. it worked for mine is all i can say maybe they coulda been better who knows but there are other threads in here explainin all u need to know and facts