It's a beautiful thing when the Potato bloom, a whole range of different colors, Yukon Gold are shades of violet, some red potatoes bloom white and some potato decide not to bloom at all, they just admire the bloom of other Potato, they probably feel shy, so there's no actual rule about the bloom of Potato, it's a festival. But a gardener knows that when a Potato does bloom it means tubers are forming, and in the end the tubers are why many of us plant Potato in Potato patches instead of as an Annual in the Perennial Border. And too when the Potatoes bloom odds are there's a gathering of the host that feed upon Potato.
Oddly these creatures tend not be Deer, or Rabbit. Rather the Feast of Potato is
celebrated by Beetle, Leaf Hoppers, Aphids and a little fly that has white
wings. Downstairs where the roots are there's Wireworms and Cutworms, there's a
Nematode called Stubby Root Nematode. And that's not even the beginning of a
list that includes the sooty poxes of fungus and the virus lifecycles that
include somebody's mouthpart. Then when the bloom of Potato is at it's end, the
plant begins to fall into a satisfaction, it's task done and the last gasp is to
fill it's tubers so that rodents might burrow and nibble which again gives the
Gardener his opportunity to learn humility. Rotation helps.