A weed plant grows at night too, actually enough that if you turned the light cycle to 24/0 the plant will grow slower. Pot or any other type of plants use the light cycle to determine when it is time to grow and when to propagate. The 18/6 or 24/0 cycles promote vegetative growth. 18/6 is the most common light cycle for vegetation. The flowering stage begins when the light cycle is 12/12. Whether it is natures 12/12 or yours, the plants will begin to flower, they don't care. You know it depends on where you live determines the light cycle too.
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