Yellowing and dropping leaves on Hibiscus

Question

Hi I live on the Gold Coast and we have had a lot of rain and wind recently, and the hibiscus leaves are yellowing and dropping. Could you advise the best fertilizer to use for this. Somebody advised to use sulfate of potash. Is this the best to use?

Answer 1

With a lot of rain, the soil could be water saturated and the roots lacking adequate aeration. That could lead to yellowing and leaf drop. Improve the drainage of water away from the base of the plant as best possible. Wind can cause drying of leaf tissue. So even though there is water, with impaired root function and drying winds, the plant could be experiencing severe physiological stress.
There are 16 major and minor plant nutrients, plus trace minerals and beneficial soil organisms. All are important for plant health. To apply only one mineral nutrient could further affect an imbalance. A soil test may be in order or you can use a complete balanced fertilizer.

https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/answers-to-what-causes-hibiscus-leaves-turning-yellow.htm

https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/hibiscus-leaf-drop.htm