The complete guide to cannabis gender and reproduction

Understanding marijuana gender and reproduction is essential to achieving the best possible harvest. However, it can be confusing. This guide will explain cannabis reproduction so that you are prepared. I’ll also discuss hermies, reveal the reasons why so many people love sinsemilla and share some ideas of what to do with a male plant.

Tip: make sure to download my free Grow Bible for more information

Cannabis plant reproduction

Unlike most flowering plants, cannabis plants
are dioecious, meaning there is a separate male and female plant, similar to humans.
Every plant possesses two pairs of sex chromosomes, X-chromosomes and
Y-chromosomes. Male plants have XY chromosomes, while female plants have XX
chromosomes. Also, like humans, there is a natural 50/50 split between males
and females.

There is a significant difference between the
gender of marijuana and humans, however.

This is because a marijuana plant can also be hermaphroditic. This means a single plant can have both male and female genitalia (a pistil and stamen).

Unlike humans, a cannabis plant’s 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.

Identifying males and females

It is critical that you know how to identify your
male and female plants. However, it can be a bit tricky because cannabis plants
do not start with gender. Plus, they won’t truly reveal their gender until they
start receiving 12 hours of darkness every 24 hours. In some cases, that is too
long to wait.

Why do you need to know?

The simple reason is this:

Females produce THC and males distract them
from it. Therefore, you want to determine the sex as soon as possible so that
the males do not fertilize the females.

To explain it further:

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.

Knowing what to look for

In terms of identifying between 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. However, if you can’t differentiate between males and females on height alone, then flowers and pistils are good indicators.

This may seem simple, but to be honest, identifying
the sex of a cannabis plant can be hard.

This is because marijuana plants don’t
disclose their gender until they are mature enough to do so. In fact, you may
not know 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.

Female Plants

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 males.  The females’ flowers will look like sacs that
grow two stigmas (they sort of look like feathers) out of them.

Here are two features of females:

• They eventually open to form
  little yellow, cream or white flowers
• They have hairy, whitish pistils
  that trap pollen from 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.

Male Plants

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.

Here are some typical features of males:

• They 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.

The male flower has 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.

Preflowers

It is challenging to identify the sex of a
cannabis plant based on flowers. This is because there is a very short window
between when they appear and when the plant is fertilized.

Instead, expert growers do this to identify sex:

They focus on finding the preflowers. These
develop at the tips of branches and on the main stem. Preflowers are the
immature first flowers that proceed the mature flowers.

Basically, it works like this:

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.

Yes, it’s that simple. It can be hard to see the difference at first, but over time, every grower gets better at it.

Other methods for identifying the sex of your plants

Sometimes, you want other options. Maybe you
need to know sooner, or perhaps you just prefer to use a variety of methods. Here
are a few other ways to identify the sex of your plants.

Look at the growth patterns.

During vegetative growth, every plant,
regardless of sex, starts to flourish. As the plants age, however, you will 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.

This method is not foolproof, and you
shouldn’t use it as a reason to throw out a plant. Of course, the last thing
you want to do is pull plants out at this early stage.

There is a reason to try it, however. It can
help you get an idea, so you know which plants to watch later on. (Note: this
works best on outdoor grown plants, as those grown indoors under artificial
light don’t usually exhibit these tendencies).

Identify where the plant sprouted during germination.

Need to know as soon as possible? Some marijuana growers have discovered a method that identifies the sex of the plants just after germination.  According to their theory, if the sprout comes out of the top or bottom of the seed, it is generally a female. Side sprouts, on the other hand, 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 with this anecdotal evidence, you
shouldn’t use this 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 simply because they sprouted out of the sides. Instead, keep track of
your predictions so that you can make an informed decision later.

Clone your marijuana plants.

This is really the only foolproof way to
determine the sex before the plants achieve maturity.

The best part about this technique is that it
is easy. You merely take a cutting from one of your plants.

Cloning in 3 steps:

1. Cut a small piece of the mother
   plant
2. Place the cutting into potting
   soil and let it grow
3. Force flowering with 12hr
   darkness/12hrs light after a few days

To identify the sex of your clones, you’ll need to keep them separate from the host plants.

This method works because, since they have 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.
However, this process can 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.

Flowering and reproduction

Once your plants have developed their sex,
they are ready for reproduction. Here’s some detail on what happens during that
process.

Female flower formation

On a female marijuana plant, a large cluster
of buds appear. This cluster is called the cola, and it consists of many
sub-units of buds. Within the cola, there are many pistils, which moderate the
female processes of reproduction. Each pistil contains the stigmas that
interact with male pollen.

Throughout the flowering process, a cola is
preparing for reproduction. The plant stretches and develops its bud sites.
These sites house groups of female marijuana flowers seeking to be fertilized.
New flowers form on the top side of these subunits, and small stigmas emerge
from the pistils. These thin structures are often recognizable by their white
hair.

They can still be pollinated even if they are
not white.  

Stigmas can sometimes die – especially after
heavy rains or wind. This will cause them to become dry and change in color
from brown to red. This does not mean that pollination cannot happen. Even if a
stigma is this color (instead of white), it can still receive pollen.

The female flower also has other hairs –
glandular trichomes. These “hairs” are responsible for producing resin on the
flowers and nearby leaves. Up close the resin looks like a ball attached to a
tiny neck. Its shape is a good indicator of how delicate they are. If you
handle the buds roughly, some of these trichomes can break off. Underneath the
pistol, you will find a smaller leaf called the stipule. It is more noticeable
before flowers are formed.

Awaiting pollination

When a male marijuana plant matures, it
releases pollen and seeks out the female stigmas. The pollen then travels to
the egg cell located inside of the pistil, producing a seed. If this process
does not happen, the female flower begins to change.

The fact is, Cannabis plants are designed to
pollinate.

The pollen from a male plant can survive for a
few days as it attempts to reach a female, increasing the cannabis plant’s
chance of survival. Pollen can survive on fabrics, and in air ducts. It can
also be stored for intentional fertilization.

Female plants also do their best to be
fertilized. Pistils grow larger when they are not fertilized. This is so they
have an easier chance of locating pollen.

However, this effect does not last forever. When the pistils are completely mature, the stigmas will die, and they cannot be fertilized. At this point, resin production will slow down or stop, and the trichomes will begin to break down.

The last opportunity for fertilization marks the beginning of the plant’s death, but it is not immediate death. Pistil maturation occurs gradually, instead of all at one time, leaving growers plenty of time to harvest.

What about autoflowering seeds and plants?

Most standard marijuana plants start to flower
at the end of summer as days start to get shorter and the amount of light
drops. Regular plants recognize that they need to start maturing before the
onset of winter, but autoflowering plants are different. They will enter the
flowering stage even if they receive a full 24 hours of light.

An automated flowering period is great for
growing in places with unusual growing seasons, or when you’d like to harvest
twice in a single growing season. This is because a decrease in daylight hours
(typically triggered by the change in seasons) is not needed for these plants
to flower.

Feminized autoflowering seeds provide the dual
benefits of a quick harvest and not needing to identify plant sexes.

Autoflowering marijuana seeds also produce
plants that are generally small and ideal for outdoor growth. With these, you
can plant a couple for every square foot. Plus, they only take about 10 weeks
to harvest. That being said, the yield and quality are not up to par with seeds
that flower regularly.

The
features of autoflowering plants  

•             Generally, 12 to 23
inches tall (30 to 60 centimeters)

•             Suitable for
outdoor growth

•             Starts flowering
automatically after around 3 weeks

•             Yield between 0.5
to 2 ounces depending on hours of sun

•            
Goes from seed to harvest in about 9 to 10 weeks

Autoflowering seeds will yield between 50 and
500 grams per m2, but this depends on how well you care for your plants.

Is it best to prevent flowering?

Many growers prefer cannabis that is not
pollinated and does not have seeds. It is called sinsemilla, which is Spanish
for without seed. Because these plants did not produce seeds, their plants tend
to have more trichome production and more potency.

It’s no wonder that many growers try to
prevent pollination.

Save
the energy for the buds

Pollination means that the plants will use
their precious energy for creating seeds instead of flowers. This has evolved
due to natural selection. Since a plant that produces more seeds is more likely
to reproduce many future plants, the trait is passed on.  Although this is an advantageous feature for
marijuana’s survival, it is not exactly what smokers are looking for in a weed
plant.

When female plants grow into maturity without
being fertilized with male pollen, they can usually produce a more resinous bud.
This is because there are no seeds to take over the valuable flowering area.

Sinsemilla
is difficult to grow

Sinsemilla weed is expensive not just because
it is high quality. It’s also because preventing pollination is hard. Your
female plants could be pollinated by male plants from up to a mile away! You
could also simply identify the sex incorrectly or wait until it’s too late to
separate the males from the rest of the marijuana crop.

If you make a mistake, don’t freak out.

While seeds aren’t always wanted, accidental
pollination frequently occurs. If you are worried that it has happened to you,
look for swollen calyx rings (beneath the stigmas). If unintentional
pollination occurs, remember that a few seeds won’t ruin a harvest.

After all, it may only be one flower, and your
plant has hundreds of them. You can either pick those seeds off or leave it
alone.

A few
seeds aren’t bad

Producing a few seeds isn’t necessarily a bad thing. If one crop is particularly delicious or potent, you want those plants to produce a few seeds. Store these seeds correctly and label them accurately so that you can identify which seeds produced the best crop later. Then, use the seeds that produced the desired traits in a future growing season.

Now that we understand the flowering stages’ role in marijuana reproduction let’s go more in-depth into the different sexes.

The female marijuana plant

Female marijuana plants take a tad bit longer
than males to reach sexual maturity. But once they do, it is quite easy to spot
them.

During the pre-flowering stage, the female
plant will grow one or two wispy white hairs where buds will form. It means
that the plant is ready to bud anytime soon. The hairs will be visible on the
main stem that connects to the nodes or branches. Once the hairs are spotted,
that is a great sign that the plant is a female.

Ensuring female plants

Female plants tend to start showing hairs even
before the flowering stage, or changes in grow light schedules, but they can
still be fertilized by a single male. Most growers dream of having an
all-female garden. This way they won’t have to deal with removing half their
plants when they reveal themselves as male. This is where feminized seeds come
into play.

Feminized seeds help improve your chances of
growing female plants.

Feminized
marijuana seeds are seeds that only produce female marijuana plants. But they
aren’t the only thing that makes a cannabis plant female. Under some
conditions, female (and feminized) seeds can become hermaphrodite plants and
fertilize themselves.

How feminized seeds are created

Are you wondering how breeders create a female
seed? Here’s a summary.

Early
methods

Early feminized marijuana seeds usually were
made with two female marijuana plants. One of the plants would have already
shown hermaphrodite tendencies, i.e., prone to produce male marijuana flowers
when it was stressed. The intersexual-prone marijuana plant is then stressed by
light cycle interruption or pruning. The stress would encourage them to produce
male marijuana flowers.

Then, the pollen from the hermaphrodite plant
is applied to the ‘true’ female (i.e., a plant that did not easily display
intersexuality when stressed). The downside of this method is that the female
marijuana ‘pollen donors’ already had quite a strong tendency to turn
intersexual. That tendency, in turn, was very likely to be inherited by the
resulting feminized seeds.

Current
methods

In the early days of feminized marijuana
seeds, hermaphrodites were a reasonable concern, but nowadays hermaphrodites
formed from feminized seeds alone are rare. Today, breeders use a technique
called rhodelization. It uses different forms of silver to force female plants
to produce male flowers.

This new, more intensive, technique produces
stable and consistent seeds.  Now, female
plants with a very minor tendency to turn intersexual can be used, instead of the
hermaphrodite plants needed in the past.

Best of all, none of the genes are modified,
so the seeds produced are female.

These female plants stay female even when
placed under harsh, irregular, or stressful conditions. This means that their
offspring have no more tendency that a normal female marijuana plant to turn
intersexual.  If anything, the parent
marijuana plants are physically modified by silver, and the seeds are produced naturally,
through pollination.

The feminized strains sold by I Love Growing Marijuana are genetically female and produced using this silver method. That’s why we are proud to guarantee that the feminized marijuana seeds sold in our webshop are as stable as regular marijuana seeds.

For more on feminizing marijuana seeds with colloidal silver read this article.

The male marijuana plant

Male marijuana plants do not produce buds, but
they will have flowers. These mainly contain pollen. These plants are often
thought of as useless or annoying, but they can be more useful than you might
think.

During the pre-flowering stage, male plants
start showing grape-like balls along its stalks. These clusters, called pollen
sacs, contain powdery pollens. Typically, after a week or two into the
flowering stage, the cannabis plant reaches maturity. As a result, the pollen
sacs will burst open and spread pollens everywhere.

While male marijuana plants are hard to
distinguish from females during growth, it is still a good idea to be vigilant
and watch out for them. Just remember to watch out for small grape-like balls
as early as the when they are seedlings.

How to use male plants

One of the most exciting times for a grower is
when your plants reveal their gender. However, if you’ve discovered that there
is a male among your female plants you may wonder what to do with it. You may
even be tempted just to toss it.

After all, what’s the point; male cannabis
plants don’t produce those delicious smokeable buds that you’re hoping for.
Don’t toss out that plant just yet. There are still a lot of uses for male
cannabis plants.

Make hemp
fiber

Both genders can be used to make hemp fiber. However,
the hemp fiber made from male cannabis plants is a lot softer and better suited
for making clothing, blankets, and tablecloths.  

Female cannabis plants are better known for
the coarser hemp fiber used to make rope and other similar things. As we all
know there are many uses for hemp. That should be reason enough right there to
keep your male plants around.

Use them
for Breeding

Male cannabis plants are a must for breeding.
Naturally, when you first start out, you’ll be more comfortable with clones.
There’s nothing wrong with that. You can always just clone your mother plant
and expect to get consistently good results.

However, I can promise you that cloning will get
boring after a while. Part of the fun of growing is the unexpected, and that is
breeding. Males make good fathers, as long as they have good genes to pass on
down to their offspring.

One of the best uses for male cannabis plants
is the production of seeds. When you’re trying to grow smokeable buds,
producing seeds might seem like an unwanted hassle. This is not the case. You
need those seeds to keep breeding.

Make
Some Hash

Contrary to popular belief, male cannabis
plants do have psychoactive properties. They contain THC, but they’re not anywhere
close to as potent as the female. That’s why you don’t try to smoke them (well,
that and they don’t have buds).

However, you can use them for hash and other
concentrates. All those trimmings, leaves, stems, etc., still have THC in them,
and that shouldn’t go to waste.

Protect
your Garden

You can also use male cannabis plants as
protectants for your garden, whether for your cannabis crops, or your regular
vegetable garden. (You know, the plants that you don’t mind showing off when
you have company over.) Male plants still contain terpenes, which are excellent
for pest control and disease prevention. You can even use them to make terpene
oils, a pretty dank pest control.

Regular seeds and male plants

Regular marijuana seeds come from one male and
one female parent and can produce either male or female plants. It is virtually
impossible to tell if a regular seed will turn out to be a male or a female
later on.

Of course, after you reach the flowering
stage, it is much simpler to identify males and females. Males will produce
oval pods while females will produce a calyx shaped like a teardrop.

The ratio for male-to-female growth with
feminized seeds is around 1-to-1 (approximately 66% female). When you start
growing, it’s in your best interest to just assume that 50% of the seeds will
end up female. You should germinate a few extra seeds to make up for all the
males that you’ll discard later on during the early flowering period.

Should
you choose feminized seeds?

Many different variables determine whether
feminized seeds are your better choice. They include:

• The conditions of the grow
• The amount of time and space
  available
• The grower’s preference
• The grower’s experience

There is one situation where you’d always need feminized seeds. That is if you’d like to breed cannabis and produce new seeds. For that, you’d need both male and female plants, which would require feminized seeds. If you have no interest in breeding and you just want to have some outstanding bud, then feminized seeds might be a better choice.

Hermaphrodite marijuana plants

Cannabis plants will do everything possible to
reproduce. Sometimes that means pollination by hermaphrodites. Yes, cannabis
plants can change their sex so that they can reproduce. This intersexual
ability is an evolutionary trait that protects the cannabis species.

So, what is a hermaphrodite?

A hermaphrodite is a plant that exhibits both
male and female reproductive capacities. Marijuana plants can easily become
hermaphrodites in response to stress in their environment.  They do this because the plant detected that growing
conditions are not favorable, which means it is less likely to reproduce.

Poor conditions mean that a marijuana plant is
less likely to survive the complete season. They also change in response to there
not being a plant of the opposite sex to pollinate them.

Although annoying to marijuana growers,
hermaphrodites (often called ‘hermies’) are an excellent survival mechanism for
the cannabis species. It is part of their genome, meaning every marijuana plant
has the potential to ‘hermie. However, some plants are more likely to do so
than others.

Why a marijuana plant hermies

Of the many misconceptions about marijuana, the
misunderstanding about hermaphrodites is probably the largest. As a flowering
plant, marijuana is not firmly one sex or the other. It’s unusual because it’s
dioecious (producing separate male and female flowers on different plants).

However, growers must remember that every
marijuana plant can produce flowers of the opposite sex under certain
conditions and it can happen at any time. These conditions could include:

• Problems in the light/dark schedule
• Lighting that is too bright
• Temperatures that are too hot
• Nutrient deficiencies
• pH problems
• Lack of water
• Poor genetics
• Feminized seeds using rhodelization

Although rhodelization is less likely to cause
hermaphrodites than previous feminization methods, there is still an increased
risk of intersexuality. This is why it is not a good idea to clone feminized
seeds. The stress of cloning (combined with its genetics) will likely cause it
to become hermaphrodite as well. For breeding purposes, it is best to choose a
mother plant that shows no signs of hermaphroditism even when under stress.

Types of hermaphrodites

There are two forms of hermaphrodites and
plants can have varying levels of hermaphroditism. However, the term is used to
refer to any plant that is not distinctly male or female.

True
hermaphrodites

A true hermaphrodite has both male and female features
growing but on different parts of the plant. This tends to be due to genetics.
In other words, the plant gained the ability at birth due to being born from a
hermaphrodite parent.

True hermaphrodites don’t always become
hermies even though they have the genetics for it. With expert growing they can
grow into females, however, under even the slightest stress they may transform
into their natural state – a self-pollinating hermie. If cloned, these plants
will always become hermaphrodites. Hermaphrodites are not as potent as female
plants, even if they flower.

Most of the time, a true hermaphrodite plant
will look like a male plant. As such, it will form grape-like balls that
contain pollens.

Female
hermaphrodites

Another type of hermie is a female plant that
forms small growths during the flowering stage. Because these growths look like
bananas, these types of hermies are often called ‘bananas.’ Until this time,
these plants appeared female, but after a while (usually due to stress) they
become hermaphrodite.

While surprising, the process of female
marijuana plants becoming male is not that rare. In fact, it frequently happens
with a female plant that goes too long without being pollinated or harvested.
As a last-ditch effort to continue the species, she becomes hermie and produces
seeds herself.

Hermaphrodites can be male to female as well, with
male marijuana plants growing pistil flowers, but this is less common.

Levels of hermaphroditism

Because a hermaphrodite can have any number of
opposite-sex flowers, there are varying levels of hermaphroditism. Here’s how
to categorize what you have:

Mostly
Female Flowers: The plant can still function as a
female by removing male flowers

Equal
Number of Males and Females: The plant will most likely
self-pollinate.

Mostly
Male Flowers: The plant will function as a male.

Identifying Hermaphrodites

It is crucial to figure out what kind of
hermie you have to know what to do with it.

Banana hermies have pollen sacs that are not
round like true hermies. This is because they are not pollen sacs. They are
actually elongated stamen inside of a pollen sac, that looks like bananas.

Want to know the crazy part?

They are also yellow and grow in bunches like
miniature bananas. However, they are sometimes lime green.

The most significant difference between
bananas and other hermies is that the “banana” pollen sacs do not need to open to
pollinate. Because they are the exposed male part of the pollen sac, they start
pollinating as soon as they appear.

This means, if you see them it may already be
too late.

Dealing with hermies

Hermaphrodites are challenging for marijuana
gardens because they make it possible for female plants to pollinate themselves
or any neighboring female plants. They’re also easy to miss if you do not
regularly inspect your garden.

Removing
hermaphrodite plants

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.

Especially with bananas, it is best to
immediately remove the entire plant before it has a chance to produce more.
Then, watch for bananas on other plants. Bananas grow quick and do their damage
even quicker. If you start to see a bunch of them, harvest whichever plants
haven’t been fertilized and consider yourself lucky.

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).

Again, the best thing to do with
hermaphrodites is to remove them.

Pruning
hermaphrodites

If you don’t want to remove the plant
altogether, you can simply pluck off the male flower bunches that appear. This
will restrain the hermaphrodite effects and keep it from pollinating itself or
other nearby plants.  It also limits its
ability to continue its own line of traits.

This option works best on true hermaphrodites,
where you remove the pollen sacs before they burst. You’ll also need to
identify every hermie and remove all the sacs in time. However, this can be
challenging since the pollen sacs can reappear after they have been removed.

Keep in mind, a few bananas aren’t a big problem. If you only have a few, just remove them.

However, the problem is that it is rare for a plant to only have a “few bananas.”

TIP: Looking to buy seeds? Visit the ILGM marijuana seed shop

Cut your losses and keep growing

In the end, you don’t need to go to heroic
lengths to save your plants. Whether it’s because you have male plants or
because they are hermaphrodites, sometimes the best choice is to cut your
losses, remove the plants, and focus on the remaining female ones. After all,
if you dedicate a lot of time to just a few plants, you can ensure that those
plants end up with the highest possible yield.

Marijuana plant reproduction can be difficult to
understand, especially when cannabis can self-pollinate under certain
conditions. As a grower, you must stay vigilant. Know how to recognize the sex
of your plants before they start to reproduce.

Happy growing!

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