Hibiscus: Help question re yellow leaves..., 1 by pheitmeyer

pheitmeyer wrote:
This is the 'San Diego' variety.

One of my first plantings in March '06 in clay soil. Back then I only amended around root ball 1 foot with mulch & gypsum :( and surrounding soil is rocky and doesn't drain well. The pink (I forget the name) Hibiscus right next to it is doing great.

It is feed palm fertilizer about every 8 weeks and I miracle growed it a few weeks ago as well.

I've done some research and can't determine if it is an iron issue or nitrogen.

Any ideas? Should I acidify the soil or does it look like a straight nutrient deficiency?