The duration of marijuana’s flowering time will depend on the cannabis type and the growing conditions. Normally, female weed plants will begin producing buds late as compared to the male plants. When the average daily photoperiod is 12 to 13 hours or lesser, the female marijuana plants will start to flower. It is almost impossible to determine the sex of the cannabis seeds but when the plants are mature, the characteristics of male and female plants become more obvious. Sexing is necessary if you want to take away the males from your garden. By pulling out all the male weed plants as early as possible, you are giving them no chance to pollinate the female plants.
1. Get a plastic-coated twist tie and a small black paper bag or something that is lightproof and similar to it. Please note that a paper bag is not suitable for high intensity discharge lamp because of the strong heat it emits. Paper bag is good to use because it permits air to flow in the absence of light.
2. Choose the weed plant you want to sex. After which, you have to select a growing tip and once you have already chosen a tip, cover it with a paper bag and seal it using the plastic-coated twist tie.
3. Stimulate the plant to start flowering by removing the paper bag after 12 hours of dark cycle and expose the growing tip to 12 hours day cycle ends.
4. In just one to weeks, you will soon notice the covered growing tip is already showing signs of its sex.
As you tie the paper bag around the chosen growing tip, do not make it too tight in order to allow air passage. Remember to let only air pass the paper bag and never allow any amount of light to penetrate during the dark period because the plant may not show its sex early.
Sexing marijuana using a paper is time-consuming because this process may put the cannabis plants back 2 weeks in growth cycle. Do not pre-force the weed plants to produce flower when they are about 8 inches tall if you do not have enough time. Sex marijuana using a paper bag to cover one branch/growing tip in order to differentiate its sex early.