do you have to cut them off when the stems go red? as they dont seem to do alot. does it hurt plant or reduce size?
If you take them off it will limit the amount of photosynthesis the plant will be able to do, also possibly slowing growth and stressing the plant. This depends on the reason you are cutting though, are you trying to make more light penitrate the canopy? Or moving plants closer together where they will shade each other? I keep a genral rule not to cut a plant unless taking clones, topping or FIMing.
You can trim them back to allow more light through the canopy, but wait till flowering is in full swing, not during vegetative growth.
I agree with woody but with one exception, I think you can trim the fan leaves from the upper 1/3 of the plant and leave the lower 2/3 to recieve the light they wouldn't get. Leafs function as a source to convert CO2, sunlight, and nutes into usable sugars as well as functioning as an energy bank to store an emergency source of energy. Plants are evry adaptable creatures and can take a lot of punishment such as trimming off leaves. Plants in general seem to function OK with animals grazing and nibbling on them in the wild over millions of years.
not only are they chemical plants but they are also waste containers. think about it...plant has to pee and crap, right? so what it does in weed's case is puts it into the 'fan' leaves and stores it...when u see them get brown and ugly...they are full and u can put it to the curb. ie. cut them off. no reason to do it unless mentioned above...either wanna get more light inside or they are ready to be flushed for final harvest. fyi...if u do cut them off...plant is just gonna make more or at least try to, wasting time and energy in the process. time is bud ya know!