Marijuana is a generally dioecious plant species, meaning that two distinct plants are needed for reproduction: a male and a female. There are also hermaphrodite or monoecious plants in which both male and female flowers grow, but still, the main psychoactive compounds only appear—in large concentrations—in unfertilised female plants. Therefore, in order to grow cannabis with high THC content, male plants should be avoided as their flowers would pollinate females, reducing the amount of THC produced.
In monoecious or hermaphrodite varieties, it is really easy to distinguish male flowers and remove them, but—in the case of dioecious plants—these are harder to identify because their male features usually show up after flowering. Additionally, even flowered dioecious plants, whose female feature is confirmed, may unexpectedly start producing male seeds and flowers under certain stress conditions.
In conclusion, this is the reason why males are cut off: to produce a greater number of females with high THC content. Pollination, on the other hand, has a negative effect since females devote their energy into producing seeds, instead of growing flowers to reproduce. What matters is getting acquainted with the different types of seeds available in the market and knowing what to expect when planting them.
Regular, feminised, autoflowering, or “quick”—each kind of seed has its pros and cons, and each fits the needs of a specific kind of grower. No matter the planting method we choose—indoor, outdoor, hydroponic, or any other—we should carry out an in-depth research about the qualities of each type of seed and their biological features so that they fit our needs and successfully produce the highest yield.
Regular and Feminised—The Ones You’ll Find Everywhere
Regular seeds are usually dioecious, although the sex of the plant is still unknown to us when planting. We must wait until the flowering stage to identify whether our plants are male or female. The disadvantage is that attention is needed 24/7 to remove the males in time before they pollinate females. But, why should we use these seeds? The answer is to obtain mother plants, which are then used for cloning, selecting phenotypes and varieties, crossbreeding and producing hybrids. The most frequent photoperiod for growing these seeds is: 18 hours of light and 6 hours of dark during the growing stage, and 12/12 in the case of the flowering stage.
Feminised Seeds—Creatures of Genetics
Resulting from research on plant breeding, feminised cannabis seeds guarantee the best flowering yield. Undesired varieties—such as those producing males—are removed, and growers have to worry less about an eventual pollination. Its vegetative growth stage lasts from five to sixteen weeks, at the beginning of which the photoperiod should be adjusted to 12 hours of light and 12 hours of darkness. This means that it is possible to extend the growing stage according to the desired size of the plant and when to start the flowering stage. Production is poorer than in the case of regular seeds, although varieties with a remarkably higher yield per square meter are increasingly available. The growing stage for these plants needs 18 hours of light and 6 hours of dark, while a 12/12 photoperiod is recommended for the flowering stage.
Autoflowering Seeds—AKA “Autos”
As a result of genetic research and the amount of existing crossbred plants, this kind of seeds are the go-to variety for amateur growers. These plants are not photoperiod-dependent, and many growers choose to provide 24 hours of light since this type of seeds allows for it. They are usually smaller in size, and their yield is poorer. As their life cycle is shorter, illnesses and pests are a less frequent problem. Most commonly, their light cycle is set to 20 hours of light and 4 hours of dark.
Quick—The Fast Seed
These are basically feminised seeds, but their flowering stage is significantly shorter—from seven to fifteen days shorter. It is worth noting that, although they derive from the cross of autoflowering varieties, these plants require a change in photoperiod to start flowering. Once they do, they grow like Jack’s beanstalk. Most growers suggest a 18/6 light cycle during the growing stage and a 12/12 photoperiod during flowering.