EARLY SEXING - Cannabis Growing Guide
It is possible to tell the sex of a plant early, and thus move male plants
out of the main growing area sooner by covering a plant is lower branch for 12
hours a day while it is in a constant light vegetative state. Use a black paper
bag or equivalent to allow for air flow while keeping out light. Be sure to set
up a regular cycle for these covered branches. If light is allowed to reach them
during the dark period, they may not indicate early at all.
Use a magnifying glass to look at the early flowers sex type. A male plant
will have a small club (playing card) looking preflower with a small stem under
it. A female flower is usually a single or double pistil, white and wispy,
emerging from an immature calyx.
Some people like to pre-force plants when they are 8" tall, in order to
weed out the males. When growing outdoors, many growers do not wish to devote
time, space or energy to male plants. Just put the plants on a 12 hours light
cycle for 2 weeks, separate the females from the males, then revert the light
cycle back to 18-24 hours to continue vegatative growth for the females. Keep in
mind, this is a time consuming process and can put the plants back 2 weeks in
growth. Do not pre-force plants unless you have lots of time. Just cover one
branch per plant with black paper (light tight, breaths air) 12 hours every day
under constant light to force pre-flowers and differentiate early.