This is a first for me, having powdery mildew on a plant. It's on my Mandevilla vine and not too bad yet.

I ordered a bag of sulfur which can either be dusted or sprayed. Most likely I'll spray, but what time of the day do I do it? I read somewhere to do it in the morning so the sun can burn off the mildew, but wouldn't it also burn the plant?

Does sulfur hurt buds and blooms? One flower did have a speck of mildew inside.