Outdoor Growing - Defan or No Defan?

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I see a lot of online resources saying to defan all the way to expose the whole buds but I do not see this practice in the Himalayas or Middle-East where cultivation takes place for many centuries now. Maybe the buds need shade to not damage the trichomes or maybe the big leaves will help to increase different qualities of the flower. 


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Defanning or in other words, removing the fan leaves from the lower 1/3 to 1/2 of the plant is a useful practice for indoor grows.  Why? 


1.  In most indoor grows, the light sources are in a fixed position above the plant.  This results in those lower leaves sitting constantly in the shadow of the upper leaves and colas.  The plant expends energy and resources to keep those lower fan leaves alive, while those shadowed leaves are unable to sufficiently perform photosynthesis to return their "fair share" of energy and resources back to the plant.

For outdoor grows, the Earth spins eastward at ~600 Kilometers per hour, giving us the impression that the sun (the plant's light source) traverses across the sky from east to west.  This "movement of the light source" allows light to reach the lower fan leaves in a random on-and-off manner throughout the day.  Add to that the occasional wind or breeze causing the upper leaves to waggle to and fro, thus allowing sunlight to break through the canopy from time-to-time, one can understand that the lower leaves would be more able to contribute their "fair share" of energy and resources back to the plant.


2.  In indoor grows, there is no natural air circulation as is found in nature. We have to provide artificial air circulation using fans and exhaust ventilation.  Failure to do so would result in stale air, the plants using up all the CO2 in the area of the leaves, resulting in basically the leaves being unable to continue transpiration.  Additionally, stale and uncirculated air more readily allows mold and parasites to take advantage of the weakened plants.  Artificial air circulation costs us energy, and as proud as we may be of our air circulation efforts, we are still circulating air within a closed-in area, still not as optimum as a clean, natural outdoor environment.  The removal of the "useless" lower fan leaves allows our artificial air circulation a better chance to avoid the above-mentioned problems.

In nature, the air moves as a result of the constantly shifting high- and low pressure waves of our Earth's atmosphere and as a result of temperature changes caused by the movement of the sun and clouds.  Sure, there may be days where the air seems to be absolutely still, but not really.  Sit outside on any day, and you will feel air movement within every minute.  And each time that air moves it is replaced with fresh ambient air.  Transpiration is able to occur basically without interruption.


If you detect that your outdoor grow is unable to receive sufficient circulation or unable to receive sufficient light in the undergrowth, then by all means, remove some of the lower fan leaves.

Take a look in YouTube at the monster outdoor grows in Mendocino County, California.  Those plants are truly leaf monsters,  maybe they defan, maybe not, but they definitely have huge harvests.


If the question is whether to "completely de-fan" (to remove ALL fan-leaves), I expect that that would not be a good practice, because the fan-leaves are basically the solar-collectors for the plant.  Without the solar-collectors, the plant would be less able to provide for its own energy and resources needs in order to produce optimum buds.

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