My mandevilla was doing great

Question

Now the leaves have black spots, are turning yellow and falling off. Any ideas? I have it in a huge clay pot on front porch. [e-mail]

Answer 1

It sounds like your plant has a fungus. Treat the plant with fungicide. I like to use neem oil as it is safe for people and pets and also will address any pest issues the plant may have. Here is more information on it: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm