The Problem: Overfertilizing your marijuana plants
Symptoms: Leaves that turn brown or look burned. Although stunted, weak-looking marijuana plants may signal that you’re not giving them enough nitrogen, this rarely happens with novice growers who tend to overfertilize. Remember that nitrogen produces leaves. In chile peppers, excess nitrogen means lots of leaves and no pods. It’s the same with flowering marijuana tops—when they’re ready to reproduce and flowering commences, the plants don’t need any more nitrogen, so it makes no sense to pamper the plants and feed them all the time.
Solution: Flush the containers and stop any fertilizing until normal growth returns.