too late to get a picture i guess? ... remember both mites and asters yellows cause the distortion of the cone and lake of petals to some extent... but only asters yellows will cause the petals to turn green.. and to have the mini flowers (stem and all) grown from the cone itself. I have seen plenty of plants that are completely infected with asters yellows and the plants still look healthy enough... it's just the blooms that give it away. In regards to the asters yellow virus living in the soil... from what i have read... no it doesn't... it needs to be living in a host plant. Plenty of common weeds can get asters yellows, so if you get true asters yellows in your garden.. it could be in the neighborhood just lurking around. If you are ripping out a plant, i would still wait a while to replant a potentially suitable plant so that all existing plant material (roots left in the ground) is dead. But why not just plant something else anyway?

Mindy - I also have A. tataricus 'Jindai.' The color is definitely a more purple-blue, but the plant is a stunner. Just started blooming for me (I believe it's generally regarded as the latest blooming garden aster) and will go through several hard frosts before giving up for the year, well past Thanksgiving for me. In fact, as it gets cooler the foliage will turn a pleasant pale yellow while the plant is still blooming. It gets 4 to 6 feet tall - although it is considered dwarfish compared to the species, which can get 7 or 8 feet tall. Yikes! It's very upright compared to the very branched, spreading bloom habit of many of the asters. The foliage is also very large and coarse - the basal leaves can be up to 2 feet tall and 4-5 inches across - so the whole large nature of the plant makes it a real eye-catcher from a distance. Can you tell how much I like this plant? - Steve

Thanks to both of you. So good to know. I quite like them. I am not too troubled by them showing up everywhere in my garden but I would not want to think that they are invasive and it would be a bit challenging to thoroughly remove the spent flowers though I could try. Across the road is a forested area and a path with tall wild plants like goldenrod and aster and beyond that a marsh. I don't want to do anything irresponsible. I understand they are short lived. Should I be concerned about them spreading to this natural area across the road?

Well, it doesn't really make sense for the mites to cause the problem, but it was just interesting that a photo on the first site when I googled came up had the black edges. It has been rainy in many places this year, and so a lot of plants are struggling. Struggling plants get more pests and diseases, that's the way it works, so maybe it would be good to look at other factors and try to get those under control, to move on towards eventually getting the mites under control. It all goes together. Kind of hard to manipulate the rain, though. At least it's dried up here. I agree a whole plant shot would be good to see, if OP is still around.