The flowering phase is when the female plant produces trichome-covered colas and when the male plant produces and releases its pollen. Cannabis plants flower naturally during the 12/12 photoperiod when the plant receives 12 hours of light and 12 hours of darkness.
In nature, daylight hours are optimal for cannabis plants flowering from July to November in the Northern Hemisphere. On the autumnal equinox in September, the sun is in the sky for 12 hours of the day, with daylight hours slowly reducing until and through the winter. The opposite is true in the Southern Hemisphere.
Indoors or in a light-controlled greenhouse, introducing an artificial 12/12 light cycle will force a cannabis plant to flower.
Knowing when cannabis is ready for harvest.
A female plant is generally ready to harvest when the glands on the top of the capillary stalked trichomes turn from clear to a milky white color.
Some cultivators are also able to use the color of the stigmas to time their harvest. Stigmas tend to change from either white to orange or red to brown.
Growers should also be aware of the typical flowering times of the cultivars they’re growing.