Marijuana plants are pruned for several reasons. The most important reason for pruning is stealth. Keeping its size down helps make sure it won’t stick out and be spotted. In addition, pruning also improves yield if done correctly. Short or shaded branches take resources away from more productive plant parts that are in bright light. Taking these unproductive branches will improve the plant’s vigor and increase the yield in the remaining branches.
It is important to prune your marijuana plants while they are still in vegetative growth. Early pruning allows the plant to halt any resource production in areas that are inherently non-productive. Fan leaves are the plant’s sugar factories, and sugar is a key component in both metabolism and growth. Clipping off the shade leaves produces less growth and, eventually, smaller buds. Shade leaves should only be removed or trimmed when they are blocking light from getting to the growing buds. If the buds are shaded by only a portion of the leaf, then you can just trim the leaf instead of removing it outright.