Im starting this grow very early in the season for my climate so cold temperatures will definitely be a challenge. Would have been better if i started a month later but i was inpatient to start growing so we will see how this goes.
yes,nitrogen toxicity.i am very familiar with this kind of leaves.happens when I abuse some nutrients that have good amounts of N.especially during stretch.some strains,not all.and not all the leaves,only the leaves on the tallest branch. very weird clawing indeed but I found out it was N overload. that leaf won't recover but no problem if you cut off N or reduce a little bit