Defoliation is the deliberate removal of leaves, usually large fan leaves, to expose bud sites, improve airflow and reduce humidity within the canopy. It ranges from removing a few leaves that shade a bud to near-total stripping at set points in flower (schwazzing).
In practice
Leaves are the plant's solar panels: they capture light and supply sugars to the developing flowers. Removing a shading leaf can help a bud underneath; removing too many cuts photosynthesis. Responses vary sharply by cultivar. Most growers who defoliate do so lightly before the flip and again around week 3 of flower.
Myth check
House position: "tuck, don't pluck". Maximise leaf surface area, like a solar farm for the buds. Stripping within reason doesn't appear to hurt yield, and some clones grow just as fast or faster after losing most leaves, while others suffer; in the founder's experience tucking helps more. Whether defoliation raises yield or cannabinoids is an open question for GenetixBay Bay Trials. Evidence: Contested. See defoliation and lollipopping and Mythbusters.
Don't confuse with
- Tucking: moving leaves aside instead of removing them.
- Leaf drop (senescence): natural yellowing and loss of leaves late in flower.
A large palmate cannabis leaf with several long leaflets on a long petiole; fan leaves do most of the plant's photosynthesis and carry few trichomes.A bud site is a node where flowers form, where leaf meets stem, or a branch tip; training aims to put more of them in strong light.Schwazzing is an aggressive defoliation method that strips almost all fan leaves on day 1 and again around day 21 of flower.The process in chloroplasts that uses light energy to turn carbon dioxide and water into sugars and oxygen; cannabis uses the C3 pathway.A cannabinoid is any compound that binds the body's cannabinoid receptors or shares the typical cannabis terpenophenolic structure; the plant-made ones are phytocannabinoids such as THCA and CBDA.Bay Trials are GenetixBay's member-run controlled grow experiments that test growing claims side by side and publish the results openly.The programmed ageing and breakdown of leaves and other tissues, in which the plant recycles nutrients (especially nitrogen) from old leaves to developing flowers and seeds.Lollipopping removes the lower branches and small shoots on a plant, usually around the flip, so energy goes to the top buds and airflow improves underneath.Tucking is moving fan leaves and shoots behind or under others, or beneath a screen, so bud sites get light without removing any leaf area.The canopy is the top layer of foliage and buds across a grow, the surface that intercepts most of the light and where yield is mostly made.
