Cannabis is a dioecious plant, meaning it has two different sexes, creating male and female plants from seeds. Unfortunately, you cannot differentiate between male and female marijuana plants during germination or the seedling stage. However, both males and females will show growth in these ganglia and will generally be distinguished within six weeks of development. Males will develop “pollen sacs”, while females will have growths that resemble thin tufts of hair.
Females produce flowers, and this initial growth is considered “pre-flowering”. Cannabis “preblooms” are the key to identifying the cannabis genus, since they develop between 3 and 6 weeks after germination. Male cannabis preblooms can appear on male plants as early as 3-4 weeks after germination. Female preblooms begin to develop a little more slowly, about 4 to 6 weeks after germination.
Some strains will reach sexual maturity faster than others. After a period of several weeks, the plant will begin to pre-flower or form a small bud in the center of a branch. One of the first signs that a cannabis plant is female is the appearance of tenuous and generally white pistilates. Instead, male plants will produce pollen sacs that appear rounded with distinct slits that extend lengthwise, a bit like a small crab claw. These are the structures that growers usually look for to determine the sex of a plant. Around the fourth week of growth, marijuana plants also begin to grow before flowering.
In a female plant, they will turn into flowers. In a male plant, they will turn into pollen sacks. You can't always see them when they start growing at four weeks, but you can almost always find them at six weeks. Keep in mind that male plants tend to develop their pre-flowers one to two weeks earlier than female plants. Those grown from clones extracted from a female mother plant do not have to worry about gender identification, since the cutting will be an exact genetic copy of the mother plant.
You can also tell if a plant is male by checking if there are small flowers or bulbs at the joints of the stem and branches. Even if you want your female plants to produce seeds, you probably don't want to use a hermaphrodite plant to pollinate them. Of course, they can be grown as perfectly good houseplants, but they still run the risk of pollinating any other female plant in the area. Once you have identified that a plant is male, remove it from the growing area to prevent it from pollinating female plants, which will reduce your THC harvest. The reason growers are so determined to eliminate male cannabis plants is that a single pollinator can nullify an entire potential crop. True hermaphrodite cannabis plants develop male and female sexual organs, but in different parts of the plant. Male plants do not produce flowers and therefore have a fairly low content of cannabinoids compared to female plants.
And even though they produce female plants 99.9% of the time, feminized seeds can still produce male plants. Identifying male and female hemp plants is essential for successful cultivation and harvesting of high-quality hemp. Knowing how to differentiate between genders early on in the growth process can help growers avoid pollination and maximize their THC harvest.