The length of time it takes a cannabis plant to flower, or grow buds. Different plants have short or long flowering times based on their genetics.
“I love growing indicas because they have a short flowering time.”
How does flowering time differ between indicas and sativas?
The flowering stage, when cannabis plants begin to produce buds, is triggered by a reduction in light—outdoors, this happens when the sun starts to go down earlier in the day after the Summer Solstice.
Indicas typically have short flowering times, around 7-8 weeks, whereas sativas typically have long flowering times—usually 8-9 weeks, or even longer.
Indicas originally grew in cold, northern climates and evolved to fit those conditions. Northern climates typically get rain and cold weather early in the season, i.e., beginning in September or October in the Northern Hemisphere; therefore, indicas adapted to finish flowering before that cold weather starts, which would cause the plants to mold, rot, and die. They adapted to have a short flowering time to fit their climate.
Sativas originally grew in warmer climates that get little to no rain early in the season; many sativas also grew in tropical or equatorial climates. Because there is little risk of rain, cold weather, and mold, sativa plants could take longer to flower.
How long do autoflowers take to flower?
Autoflowers, or Cannabis ruderalis, grew in even more extreme, harsh, northern climates, with an even shorter growing season than indicas. These short, small plants get their name because they automatically flower a few weeks after seed germination; flowering is not determined on a reduction in light.
Flowering times are similarly shortened—the entire life cycle of an autoflower can be as short as 65 days (or 9 weeks), the amount of time it can take for a sativa to only flower.