Gorilla Glue #4 Outdoors (Newbie #1)

I seem to be having the same trouble with all my plants right now. I'm getting yellowing from new growth and I'm currently thinking its wither lockout from the high temps we've been getting so early in the season or my potting soil (Happy Frog) is running out of Nutrients. I mixed up a 0-0-13 spray I use on my farm and decided to give it a foliar spray to see if the lack of phosphorus could be the problem. If it helps or I don't see any change I may give it a shot of Tiger Bloom and Grow Big. This is puzzling me because even the plants I transplanted 2 weeks after these are showing the same signs. Can't be lack of nutrients????? I've been watering from the faucet which has a iron remover and softener and have been lowering the PH to 6.5. May try lower the PH a bit more just to see if that helps....... Other then that, everything has been growing well. Haven't been able to do a lot of LST on this plant with farm season under way, but will start it this coming week before its to late. Still trying to figure out which branches get tied down and which ones I bend to keep level. Its a learning experience for sure.