Q.yellowing plumeria leaves
the leaves on my plumera plants are turning yellow. The plants are potted and are watered regularly. I have been fertilizing with half MiracleGro and epsom salts about once a week. water sometimes two times a day account of sizzling weather. They are not in the sun all day.
Yellow leaves could be watering issues. Make sure your watering the plants evenly, moist soil.
Plumerias are susceptible to a fungal disease called plumeria rust. It first appears as many tiny, yellow, powdery spots on the undersides of the plant's leaves, giving them a mottled, yellowish appearance. Eventually, the leaves turn a uniform, bright yellow, then become brown and drop from the plant. If the infection becomes widespread, a plumeria can lose most or all of its leaves, causing severe stress and potentially killing the plant. Once present, it's not possible to cure plumeria rust, but you can help prevent it by planting where air circulation is good and by keeping the area clean.
A plumeria that's infested with pests might develop yellow leaves -- the most likely culprit is a tiny pest called the sixspotted spider mite, although other types of mites can also infest plumeria. Pests can be treated with Neem Oil.
https://www.gardeningknowhow.com/ornamental/flowers/plumeria/growing-plumeria.htm
https://www.gardeningknowhow.com/ornamental/flowers/plumeria/how-to-fertilize-plumeria.htm
