Question
I live in Gilbert Arizona where the summer temperatures average triple digits from June through August.   I bought 15 gallon hibiscus last year and they are thriving in light of having Eastern Sun exposure.  They are about 3 - 4' tall and the upper leaves have a veiny green look while the remaining part of the leaves are light green, borderline yellow.   I went to a local large nursery (where I originally bought the plants) and they recommended "hi yield" 50+ phosphate fertilizer.   What's your thought?

Answer
Hi Ron,
Thanx for your question.  I lived in Phoenix back in the late 70s.  I'm going to have to disagree with the high phosphate.  I'd use a balanced 10-10-10 or a 7-2-7 fertilizer.  Here's a link to professional tropical hibiscus enthusiasts and I think they know their stuff.  Western soils are already high in potassium and phosphorus and phosphorus will build up in the soil.  These plants like soil that is slightly acidic too.  I hope this helps.
Tom

http://www.trop-hibiscus.com/bfertins.html