My Arabian Jasmine doesn't look so good. All the leaves seem to be drying up at the base. The upper leaves are wilted, and it appears that it has powdery mildew on some of them. When I woke up there was a trail of ants trying to get to it. I've looked for aphids but either I'm not seeing them, or I just don't know what I'm truly looking for. I've read about a baking soda mixture for the powdery mildew but will that do more harm in our heat, or is there anything I can do at this point for PM or insects?