When should you defoliate during flower?

Ok so.....defoliation is a greatly misunderstood technique that gets done wrong A LOT. Most that ask about it have no real business thinking about doing it, they'll have one or two tiny plants in the middle of a nearly empty tent lol. You, on the other hand, are doing a SOG(sea of green) grow and a defol is going to very likely be needed in the near future. At 12 inches I don't think I'd do it yet though, let them stretch more. A lot of people think they should defol from the top down but really I find it's best to go from the bottom up. Start by striping out branches that don't reach canopy level, aka the lollipoping Organo mentioned, then if things are still congested(from a side view, not the top) start targeting clusters of leaves that hinder airflow. Try not to remove upper leaves unless they're really bunched up and collecting moisture. At your humidity/temp levels, moisture on the leaves are NOT your friend. Prime environment for white powdery mildew. When unpracticed at defoling, start lightly. You can always come back and remove more leaves later but you can't glue them back on if you go overboard.

Hello. Everything Organo says is true. Some people do that. I train though. I find training to work with some rules. If you take more than 1/3 of the leaves off a plant it will send it into shock and it won't grow again until it heals. Do a light LST 4 days before flip and do a final LST before the resin starts at about 3 weeks from flip. When doing LST take off leaves that block light, block air flow especially in the center, leaves that are on the bottom that don't get light. Also be aware to remove the small bottom sucker branches. Also leave 4 to 6 fanleaves at the ends of the longer branches, the plant will use them later. Chuck.

No, do not defoliate at all unless you are having massive problems controlling high humidity. Try tucking/bending leaves out of the way instead, along with some well considered "lollipopping". The fact is, those big leaves are THE energy machines that power the flower growth. Less leaves = less energy being made = less potential growth......that's how plants work. If you are determined to remove your plants energy making leaves because of internet bro science, leaf removal would not be done until after the "stretch" and after 3 weeks of actual flowering, not 3 weeks after the flip. So, about 5 weeks after 12/12. Personally, I have not defoliated my plants for over thirtyfive years and consider it as "plant mutalation/torture", not an "enhancement technique". Remember......less leaves = less energy being made = less potential growth. The big older leaves are also storage sites of essential elements the plant will draw upon during flowering, things like carbs, sugars, enzymes, nutrients etc.. It is more efficient for the plant to re-use these elements from its older leaves than it is to grow flowers AND make new elements. Therefore, rather than putting all of the energy into flower growth, the plant must use some energy making new carbs, sugars, enzymes etc, resulting in potentially smaller flowers. This re-use of elements from the older leaves is the reason behind the "fade" at the end of the plants maturation cycle. Besides, if the plant would not NEED those leaves, it would not grow them in the first place!