I have asters in my garden which have moved themselves around. Some look great and others, the leaves dry out from the bottom before the blooms come out. Suggestions to prevent this??
Asters provide such a fantastic burst of colour in the garden at this time of year that it is no wonder we love them so much that we are happy to overlook their susceptibilities. Asters are vulnerable to many fungal problems that do not kill them, but do cause them to lose their lower leaves. They are also susceptible to powdery mildew, which causes leaves to wither and die. Fungal infections can increase in prolonged periods of wet and humid conditions, so efforts to thin plants around your asters to increase air circulation may be helpful. Removing spent plants and leaves in the fall is also advised. In your garden, there may be differences in location and growing conditions that allow some asters to escape these pathogens. In terms of aesthetics, positioning some lower-growing plants in front of asters with unattractive lower leaves can help to hide them from view, but that is of course only once you know where they are going to turn up: as you have noted, in optimal conditions asters will self-seed vigorously and you will find them in unexpected places.