Why are my Pink Dahlias Yellow?
A few weeks ago I bought some Dahlias and one of them had this vibrant pink flower. I have a container garden so I potted it in regular potting soil. Watered as usual. It's doing fine except all of the new flowers that are coming up out of this same plant are a bright sunny yellow?! Is there some kind of additive or acidity need for dahlia I didn't know about? How can I get my pink flowers back?