by Jorge Cervantes
Pre-Flowering
Marijuana is a dioecious plant, being either male or female. however, intersex (aka hermaphrodite or bisexual) plants with both male and female flowers can also occur.
Pre-flowers are the first sign of a plant’s sex. The pre-flowers grow at branch internodes just behind the leaf spur or stipule about the fourth week of vegetative growth, when the plant is six to eight weeks old. This is the point of sexual maturity, the first sign a plant is preparing for flowering – the next stage in life.
You can see pre-flowers with the naked eye, but a 10x to 30x magnifier will make viewing easier. You can accurately determine plant sex after eight weeks. Using this method, you can distinguish sex before inducing flowering.
Plants grown from seed under an 18/6 day/night photoperiod will generally show pre-flowers before plants that are given a 24/0 day/night photoperiod. Once pre-flowers are distinguishable as male or female, plants can be induced to flower with a 12/12 day/night photoperiod.