I'm asking for a friend who is puzzled. She purchased this dahlia five years ago. The first four year all the tips of the petels were uniformly white as she expected. She divided the tubers at the end of season last year. This year they have been coming up with random white tips.
Any thoughts on why this happened? Is it a type of reversion? Or perhaps something caused by the division?
Someone suggested it might be caused by something in the soil she added last year.