GMSgrowsanswered grow question 4 years ago Purple/red stems and leaves happening in a non purple trait plant is usually a sign they were not being given enough feed. This is my signal while the girls are veging and I see the stem of the leaves starting to turn a little purple/red then a 50 to 100 ppm increase in food follows that. This is only while girls are veging. Non purple trait plants can and usually do show some purple/red in the leave stems while in flower. Cheers