26. EARLY SEXING

It is possible to tell the sex of a plant early, and thus remove males, in an early stage, by covering a plant’s lower branch for 12 hours a day while it is still in a vegetative state. Use a black paper bag or equivalent to allow 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 pre-flower with a small stem under it. A female flower is usually a single or double pistil, white and wispy, emerging from an immature calyx.

OTHER METHOD OF SEXING

You can also put plants in a flowering mode (12-12 light regime with 12 hours of darkness per day). When it is a clone or when it is a mature plant they  will normally start showing signs of their gender in about 10 days. In case of a freshly germinated seed, gender signs will be shown when plant is mature, in about 4 weeks of the 12-12 light regime. So, when the germinated seed is in a flowering mode (12-12 light regime) from the beginning, the gender can be detected in about 4 weeks. When the gender is clear, male plants can be removed and the females can be put in a growing mode, with 18 hours of light per day. This way of sexing is quite stressful for the plants and sometimes they will even start to produce one-fingered leaves. But, normally the plants will completely recover after some time.

Male pre-flowering.

Female pre-flowering.