From what I understand, you should trim fan leaves 1 week prior to harvest.

I hope this helps

-turtle420
turtle420 Reviewed by turtle420 on . Trimming fan leaves When do you guys think a good time for trimming fan leaves would be. My plants are about two weeks into flowering 4ft tall with tons of 12" fan leaves. Does the extra light help bud to develop quicker, what are the advantages/disadvantages to doing this. Thanks guys Green leaves Rating: 5