Quote Originally Posted by GraziLovesMary
If you would like I will post an explanation of why the leaves turn purple...
Chlorophyll breaks down at extreme temps, exposing the other pigments produced by the plant.

As for that plant having once been green, meh, it's a possibility but plants that were intially green, even after being exposed to cold temps, often still show green in the lower leaves when temps drop. I have to go figure out what book it was that had that plant- I want to say it was Greg Green's breeding book actually, but I may be wrong.

Purple plants may be a little MORE stealth but I'm still not gonna be planting one in my vegetable patch for damn sure.