Identifying the Sex of Your Marijuana Plants:
When you’re thinking about growing marijuana, you may neglect to consider some of the subtler aspects, such as organizing your plants according to their sex. Perhaps you didn’t realize that plants even had different sexes.
It is critical that you know how to identify which of your plants are male and which are female. They don’t start with a gender. The plants won’t truly show you until they start receiving 12 hours of darkness each 24-hour period, and in some cases that is too long to wait. You want to determine the sex of your plants as soon as possible so that the males do not fertilize the females. Females without seeds (sinsemilla) have higher levels of THC, whereas males produce significantly less THC. Preventing pollination, therefore, is the best way to ensure the highest quality buds.
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Marijuana can be male or female
Like humans, marijuana plants have gender, possessing two pairs of sex chromosomes, X-chromosomes and Y-chromosomes. Male plants have XY chromosomes, while female plants have XX chromosomes. In the wild, there is a 50/50 split between males and females, but as a grower, you can alter these odds.
The sex of a marijuana plant can be altered because, unlike humans, their gender depends not just on their genetics but also environmental factors. That is one reason why, when growing marijuana, you should be familiar with the different traits of female versus male plants. Each gender has unique qualities that may or may not be desirable in your garden. Females can produce potent weed, while males are useful for seed breeding.
In terms of identifying the two, in general, males have flowers, while females have pistils. Males tend to be taller as well. All marijuana plants have flowers at some point, but, if you can’t differentiate between male and female just by height, then flowers and pistils are good indications of sex.
Getting marijuana plants to reveal their gender
Marijuana plants don’t disclose their gender until they are mature enough to do so, making it difficult to know what sex you have until your plants are almost ready to begin pollination. If you wait this long to identify the sex of your marijuana plants, then it’s probably too late to grow sinsemilla buds. Here are a few techniques to quickly identify the sex of your plants.
Look at the growth patterns. During vegetative growth, every plant, regardless of sex, will start to flourish. As the plants age, however, you will begin to notice subtle differences in their sizes. Some marijuana growers have even noticed certain signs early on that can help determine the sex.
Females tend to have more complex branching when they progress from the seedling stage to the vegetative stage. Males, on the other hand, tend to be slightly taller and less filled out. Of course, the last thing you want to do is pull plants out at this early stage, but this can help you get an idea, so you know which plants to watch later on. (Note: marijuana plants grown indoors under artificial light don’t usually exhibit these tendencies).
Identify where the plant sprouted during germination. Some marijuana growers have discovered a method that helps them sex the plants just after germination. If the sprout comes out of the top or bottom of the seed, it is generally a female. Side sprouts generally turn out to be male.
While this hasn’t been scientifically studied, growers who have used this method report a 90% success rate. Even so, you shouldn’t use this knowledge as absolute fact. Let the plants grow a little and try to notice any distinctly male or female signs. Don’t just throw away the marijuana seeds if they sprout out of the sides. Instead, keep track of your predictions so you can make an informed decision later on.
Clone your marijuana plants. This is really the only foolproof way to determine the sex before the plants achieve maturity. You simply have to take a cutting from your plants. Place this cutting into potting soil and let it grow on its own for a few days. Then, force flowering with a 12-hour period of darkness and 12-hour period of light (the clones must be separate from the host plants).
Because the clones share the exact same DNA as their host, they will have the same sex. Once the clones go into the flowering stage, it will be easy to determine their sex and the sex of their hosts. Make sure you keep track of which clone came from which host, so you don’t get things mixed up.
You can also force flowering of a regular plant (not a clone), and put it back into veg stage once you know it is female but this process can actually cause more trouble than it is worth. While effective at speeding up the reveal process, it can also place unnecessary stress on a developing plant.
Identifying the sex
Once the gender is revealed, you need to begin separating between the two sexes. If not, your plants will likely pollinate, reducing the potency of your weed. Learning to identify the sex of your cannabis plants can take some practice, but it is not impossible.
Female plants are often very recognizable. While both males and females will form flowers, the flowers from female plants usually do not bloom until after the male plants. The females’ flowers will look like sacs that grow two stigmas (they sorta look like feathers) out of them. They will eventually open up to form little yellow or white flowers. The hairy, whitish pistils will be sticky enough to trap pollen as it is dropped from taller males.
You’ll find the stigmas in a node region of the main stalk. This is where a branch grows from the main stem, or where a branch grows from another branch. Female flowers are generally cream or white in color.
The easiest way to identify a male is by its rapid maturity. Males mature faster than females, meaning they will grow quicker and become taller about two weeks before a female plant. This is so they can drop pollen on female plants. Their flowering phase can begin as much as a month before females, giving growers some time to identify them.
Male cannabis plants tend to grow straighter and don’t develop as many flowers as females. The flowers are generally located at the top of the plant. Unlike the female flower, male flowers are tight green clusters. There is a central part that looks like petal-shaped objects, five of which are inside of the sex organs. To the untrained eye, they look like a tiny banana bunch. Male flowers are sometimes called “false buds” since they are actually pollen sacs. These clusters begin opening over time until a stamen appears – ready to pollinate the females.
When looking for male plants, you should focus on finding the preflowers. These will develop at the tips of branches and on the main stem. Preflowers are the immature first flowers that proceed the mature flowers. If you notice a raised calyx on a small stem or stalk, then it is most likely a male. If this calyx isn’t raised, then it probably a female plant. It can be difficult to distinguish between the sexes at first, but over time, every grower gets better at it.
Sometimes, you’ll have hermaphrodites. This is an evolutionary trait to protect the cannabis species. No matter how hard you try to prevent it, marijuana will do its best to reproduce, even going to the lengths of reproducing itself when there aren’t any male plants nearby.
Hermaphrodites are basically plants that exhibit both male and female reproductive capacities. They can occur as a result of environmental stress, meaning this mixed-gender could develop at any point in the growing process. They are challenging for marijuana gardens because if female plants begin to grow male flowers, they can pollinate themselves or any neighboring female plants. They’re also easy to miss if you do not regularly inspect your garden. Hermaphrodites can be caused by poor nutrients, too much nitrogen, and particularly cold weather. They can also develop in plants that have been forced to flower.
Self-pollinating hermaphrodites generally lead to more females and more hermaphrodites. Therefore, when you spot a ‘hermie’ in your all-female garden, you may want to practice culling. Culling is the process of removing plants with undesirable characteristics so that your overall product does not exhibit these same traits. In other words, throw away your hermies.
If you don’t want to remove the plant altogether, you can simply pluck off the male flower bunches that appear on your hermaphrodite plant. This will restrain the hermaphrodite effects and will keep it from pollinating itself or other plants nearby, and, therefore, will limit its ability to continue its own line of traits.
Some growers have been able to salvage hermaphrodites since they can sometimes still produce decent amounts of THC. Others have tried to hack this system by creating hermaphrodites out of male plants (with little to no success). The best thing to do with hermaphrodites is remove them.
Why you may want a single-sex garden
Identifying the sex of your plants is important because it helps prevent pollination. Pollinated female plants will stop focusing their valuable energy on their flower growth. Instead, they will use it for seed production, making it undesirable for a successful harvest and a high yield. This doesn’t mean marijuana plants have to be seedless. Pollinated female plants can produce flowers and seeds simultaneously. Doing so is challenging, however, as the plant would need to be extremely healthy to do it successfully.
Removing males and hermaphrodites has other benefits as well. The plants that remain will receive more sunlight, and you can focus your efforts on fewer plants, making your work more effective. Besides, male marijuana plants are not particularly good for smoking, so they are not worth harvesting in the end.
Technically, you can leave males and hermaphrodites in an outdoor garden, but they must be kept away from the female plants. (Remember, pollen can travel by wind). Males are useful for producing seeds in desirable females, and their leaves can be used to make edibles such as pot butter.
If you’d like to remove males and hermaphrodites from your garden the process is quite simple. If growing outdoors, uproot the plants from the ground by removing the dirt, and separate any neighboring roots if there are any. If growing indoors, remove it from your garden and dispose of it.
Try to do this as early as possible. Once a male shows his flower, it’s a good chance that the pollen has already been released. Removing male plants will reduce this risk and likely lead to a much more successful yield, but it doesn’t always remove the risk entirely.
Sometimes, depending on where you are growing, male plants could be within a close enough range to pollinate your female plants. This can happen from male plants that are being grown by someone else, as well as wild ones. Pollen can travel as far as several miles in the wind as well as on birds or bees. Cannabis plants have evolved to be very good at distributing pollen to encourage the survival of their species.
Perhaps the best defense against pollination is buying female seeds, to begin with. Feminized marijuana seeds will develop into female plants, reducing the need to worry at all.
The founder of I Love Growing Marijuana, Robert Bergman, is a marijuana growing expert that enjoys sharing his knowledge with the world. He combines years of experience, ranging from small-scale grows to massive operations, with a passion for growing. His articles include tutorials on growing... [read more]