Q.Why my plant turn yellow
Hi,
I have bought thai jasmine plant n frangipani tree 6 months ago, I notice thai jasmine n suimei started to turn yellow. Frangipani tree leaves starts to hv black spots. I do not know what happen it due to too much water. Appreciate yr advise.
B.rgds
Sheena

Pests, incorrect watering, unbalanced pH in the soil or nutrient deficiencies are the most common reasons for Jasmine plant leaves turning yellow. This article may help you identify exactly what the issue is:
https://www.gardeningknowhow.com/ornamental/flowers/jasmine/jasmine-leaves-turning-yellow.htm
Frangipani (Plumeria) need at least six hours of full sun plus deep, deep watering and then be allowed to dry out in between waterings.
This article may help you with your Fangipani:
https://www.gardeningknowhow.com/plant-problems/disease/black-spot-fungus.htm