Hello, I have a plant sold to me as "boltonia asteroides" about fifteen years ago. Every year it has blossomed profusely with white flowers. This year we dug out a section of it and planted it in a different bed. The remainder stayed in the bed where it has been for fifteen years. Both plants this year blossomed with yellow flowers. Has anyone ever seen or heard of this? I googled extensively and could find no mention of this phenomenon. Does anyone have an explanation?
Thanks for writing. Unfortunately, I have no idea what's gone on with your plant. In most cases when I hear from readers about a plant changing, it's usually that another seedling has gotten mixed in and taken over. I'd wait and see what happens next year --- if it comes back yellow again, take a sample to the folks at your cooperative extension office to take a look at it. They may be able to help better after seeing it in person.