Female Pre-flowering

Marijuana Horticulture

by Jorge Cervantes

Near the end of normal vegetative growth, plants grown from seed develop pre-flowers. This is when female calyx formation initiates, and it is not contingent upon photoperiod. It occurs when a plant is old enough to show signs of sexual maturity, about the fourth week of vegetative growth, or six to eight weeks from germination. The pre-flowers emerge behind the stipule at the fourth to fifth branch internodes.

A pre-flower looks like a regular female flower; most have a pair of white fuzzy pistils. Pistils normally form after the light green seed bract part of the pre-flower has formed. Wait until pistil have formed to ensure the plant is a female and not a male. The pre-flowering stage lasts from one to two weeks. A little patience is in order now!

Plants grown from seed under a 18/6 day/night photoperiod will usually show pronounced pre-flowers before pants given a 24/0 day/night photoperiod. And under a 16/8 day/night regimen pre-flowers show more quickly and are often more pronounced. As son as you can distinguish pre-flowers as male or female, plants can be induced to flower with a 12/12 day/night phtoperiod.

Wait to induce flowering until pre-flowers have appeared. Inducing flowering with 12 hours of uninterrupted darkness and 12 hours of light before pre-flowers set will stress the pant. Such stress could cause strange growth, and plants may grow into hermaphrodites. Inducing flowering before pre-flowers develop does not make plants flower faster. Plants will flower about the same time as if you had waited for the pre-flowers to develop.