Q: I transplanted several runners from a white berried nandina to a different part of my yard. Now that they are maturing, they’re displaying red berries, not white. Can you think of any possible explanation?
A: The white (or yellow)-berried form of nandina is a genetic sport of the common red-berried one. If you truly got root sprouts from the white-berried plant, they would produce white berries. But my bet is that the sprouts you dug came from white seeds dropped from the mother plant. As such, they have a great propensity to switch back to their red-berried ancestor. If you collect and plant lots of white berries, some will yield white-fruited plants but most will sport red berries.