Just a guess but if its in soil then its probably due to low light or bug damage from when it was younger. The plant will eventually shed any leaves that are injured or non functional. If its hydro then I'll leave it to someone else to take a stab.
elcheapo Reviewed by elcheapo on . Question (Day 17) I left this question in Basic Growing, but it quickly got off track when people started focusing on my lights rather than the question i had, so i figured i would try posting in here. Day 17 growing Northern Lights under 400W HPS (yes i know HPS is not optimal for veg). So far I am seeing incredible growth, already 5 nodes with a 6th looking like it is about to form (so it is a prett big plant). My question, or concern rather, has to do with the first set of leaves turning yellow and Rating: 5