I live in Richards Bay in KwaZulu-Natal. I have recently planted a hibiscus, but the leaves are going yellow and dropping off. It really seems to be battling. It is in full sun and I water regularly and feed with 615.
Certified GKH Gardening Expert
This article should help you with that: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/answers-to-what-causes-hibiscus-leaves-turning-yellow.htm