what causes a plants leaves to start turning purple? i was talking to my buddy, and he mentioned some of his leaves are turning purple. *these are mostly seeds i gave him.. there may have been a few purple kings in there, but i highly doubt it. i remember reading about some nutrient defficiency years ago.. i mentioned maybe N.. but i'm second guessing myself now, as i'm not a great grower to begin with, and learnt most of my knowledge long ago. he doesn't care. but it's bugging me now, so i turn to you. (i know it could possibly be many things, but is that an effect of a deffiency?) thanks *hate to post this. but it's bugging the heck outta me, and i couldn't find anything with searches.