Hello, This is my second year with this problem and while it only bothered my asters it seems it now likes my snapdragons. I know once a plant is infected it can't be cured. But if I water correctly and fertilize get it stronger to fight the disease? My asters are lime green, but the leaves still look healthy. They are large and pointed up, as if they are happy. I've started these in the greenhouse and grown them under insect cover since I put them outside. I haven't a clue how they got infected with being so careful. I have 3 plants I left in the greenhouse and they are healthy. I guessing you have to grow Asters in a greenhouse for good results. I had two years where I was able to grow them fine outside, but not the last two years. So frustrating.