Question
hii, i have about 6 mandevilla vines growing very tall and flowerign nice but the ones i have in the front yard got black/brown ink like substance on the front of the leaves  it can come off if i wash the leaves with water but it on all the mandavilles that are in the front yard which gets enough sun. i want to know what could be the cause of it. is it a disease? or fungus? what could be wrong with it and what can i do to help it go away or prevent from other vines gettign it?

Answer
Tehmina,

I need to know where you live so I know your climate? I can think of 3 possibilities that it could be. A type of mold, a type of fungus, or a bird excrement. From what you said I understand that you can wash it off? When you wash it off does there appear to be any damage to the leaves? Is it sticky before you wash it off? Let me know and I will try to give you more advice.

Darlene