My potted Hibicus has lots of yellow leaves.
I have 2 separated plants around my pool. One has a minimal amount of yellow leaves. The other one is mostly yellow leaves :/
Certified GKH Gardening Expert
They benefit from extra water during the summer, just enough to keep the soil slightly moist, and they are very heavy feeders.
Usually feeding them will bring the color back. This article will help: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/answers-to-what-causes-hibiscus-leaves-turning-yellow.htm