Cannabis plants go through two stages of life, the “vegetative” stage and the “flowering stage.”
They first go through the vegetative life stage, which you can sort of consider its “childhood” since the plant is only focusing on growing bigger and taller, and gender doesn’t matter. At the beginning of this stage you usually can’t tell what the plant’s gender is.
However, once the plant is about 6 weeks old, it will usually show signs of “pre-flowers” which will alert you to the gender before the beginning of the flowering stage.
Next, cannabis plants switch to the flowering stage which means they stop growing bigger and taller, and instead spend all their effort growing flowers (the buds we want are flowers!). The flowering stage is like the “adult” stage of a cannabis plant since at this point it’s only interested in adult stuff like growing their male and female parts, then pollinating In the flowering stage, plants start growing buds or pollen sacs in earnest. The buds we want are female flowers, so growers generally only want to grow female plants.