Sexing Cannabis: Is My Plant Male or Female?

Sexing cannabis plants is a crucial step for a successful harvest. Many new growers feel nervous about determining the sex, as experience does count. However, knowing exactly what to look for, setting the correct light schedule and giving plenty of attention is all it takes. A magnifying glass will come in handy, as the sex organs are super tiny.

Why is sexing cannabis plants important?

A cannabis plant typically produces either male (pollen-producing) or female (seed-producing) flowers. Cannabis grown with the intent of harvesting THC-rich buds requires non-pollinated female plants. In that case, keeping the sexes separate is vital. It takes just one male plant to fertilise a whole room of females, so act quickly.

How to see if your cannabis plant is male or female

Around 6 weeks after germination (outdoors), or 1 week after initiating the flowering stage (indoors), the tiny buds (sex organs) begin to develop at the nodes of your plant. The male plants will develop pollen sacs that resemble a bundle of balls. These can appear a week or two before female flowers, and won’t grow hairs. At this point, you can start trying to distinguish the sex of your cannabis plant:

  • Look 3-5 nodes up the stem (about halfway up).
  • Study the tiny buds growing at the nodes.
  • Female: look for 2 thin hairs (stigmas), growing out of a slightly open tear-dropped bulb (bract).
  • Male: look for 2-3 pollen sacs, resembling balls and surrounded by flowers (males will not grow stigmas).

Female cannabis plant

Female plants will show tiny, pointed buds, and produce two white hairs.

Male cannabis plant

Male plants will show a few small balls on stems, quickly growing larger with a few flowers present.

As time passes, visible changes to your plant will be observed, though some strains can take longer to develop than others. If you’re unsure when sexing your cannabis plant – take a step back and wait one more week. By 8 – 10 weeks after germination (outdoors) the flowering stage should be well underway and sex should be obvious.

Now and again, plants will present with both male and female flowers and are known as hermaphrodites. This can occur for two reasons: genetic predisposition or environmental stress to the plant during the flowering stage. It’s most likely to happen towards the end of the flowering period, so do keep a close eye on your plants. Like males, you’ll want to keep hermaphrodites separate from your female plants, to prevent pollination.

You can lower the risk of hermaphroditism occurring by choosing a feminized autoflowering strain.

When to induce flowering, and when to sex cannabis plants

At around 6 – 8 weeks old, cannabis is ready to transition into the flowering stage. Flowering is induced when the light schedule follows 12 hours of sunlight and 12 hours of (uninterrupted) darkness. Indoor and outdoor plants follow the same basic light schedule, unless they are autoflowering.

Pre-flowering buds can be observed under a magnifying glass within the first ten days of adjusting the light schedule. At this stage experienced growers may begin to detect plant sex, but don’t worry if you’re not sure, just wait a little longer.

Flowering cannabis while growing outside

Towards the end of summer, the hours of sunlight in a day begin to decrease, and the amount of darkness your plant is exposed to will increase. Wait until the hours of light per day reach 12 hours and ensure plants receive 12 hours in complete darkness. About 10 days after this point (usually the summer solstice in the northern hemisphere) you can start to check as above.

The choice of cannabis strain will vary depending on the climate, and the months of flowering are determined by whether you are growing in the northern or the southern hemisphere. 

If you are in Northern or Eastern Europe, you are in the cool-temperate zones. This means your cultivation season typically begins late April to early May and through to the end of September. Northern summers are short and mild with usually only a single outdoor harvest per year. Indica strains tend to grow well in cooler climates.

Southern and Western Europe are in warm-temperate zones. Southern summers are typically long and sunny, and the good weather can last until late October. Ideal circumstances to cultivate late-flowering varieties like sativas.

Keeping a close watch can help you figure out what stage of flowering you are in. Before true flowering begins, there is a stage known as pre-flowering, and this is when the plants will start to display male or female characteristics. Outdoors, pre-flowering usually begins about six weeks after germination.

If you can see the 2 white ‘hairs’ (the stigmas) growing at the plant’s nodes, but no buds have developed yet, you can safely assume that the plant is female and you are about to begin the flowering stage. If you can’t see any hairs, wait another couple of weeks and keep checking every couple of days to see if they are developing, or if balls are starting to develop instead.

Flowering cannabis for growing indoors

It won’t matter where in the world you are – when growing indoors, simply adjust the timer on your lights to follow the 12/12 light schedule. This is the beauty of growing indoors, because you can easily track what stage of flowering you are in and manipulate the plant growth cycle to induce flowering.

Can I avoid sexing cannabis plants?

Sexing cannabis plants will only be necessary if you’ve purchased our regular seeds such as Skunk #1, Jack Herer, and Master Kush. Those seeds will turn out to be roughly 50:50 male/female plants (on average) and are great for testing and developing your cannabis sexing skills.

Avoid sexing altogether by sticking to our feminized seeds like Northern Lights Feminized, Hindu Kush Feminized, and Afghani #1 Feminized. All our autoflowering seeds are feminized, and our cannabis strains range from having a short flowering period to strains with a relatively long flowering period, depending on your grow goals.

It may take some time before you feel totally confident sexing your plants, so don’t be afraid to experiment. Remember to stay patient and observant over the next 3-4 weeks. Keep a strict 12/12 light schedule and avoid stressing out your plant. If you still have questions, or have any tips for germinating cannabis seeds, please share them in the comments below.

  • Disclaimer:
    Laws and regulations regarding cannabis cultivation differ from country to country. Sensi Seeds therefore strongly advises you to check your local laws and regulations. Do not act in conflict with the law.


17 thoughts on “Sexing Cannabis: Is My Plant Male or Female?”

  1. Your plant probably flowered early and your plant was probably ruined. Never plant before March 1st even in AZ.

  2. Hello great video I created an app to help beginner growers distinguish male pre-flower from female, it works with pre-flower only and is just a help, regards

    1. Mark - Sensi Seeds

      Good afternoon MasterWeed!

      Thanks for the comment,
      That sounds great – I’m afraid the link in your previous comment was incorrect. What was the application called?

      Best regards,


      1. Mark - Sensi Seeds

        Good morning Linda,

        Thanks for your question, and I hope you’re having a good day,
        The application was created by MasterWeed, and sounds very interesting!
        Unfortunately, the link is broken, so i’m waiting for MasterKush to send us the correct link 🙂

        Have a great day,


  3. So I’m a little over or right at two months of strong growing. My plants look great they are happy and so far I only found on distinct male and he is gone out of the house. I have two more that I’m unsure of because they look like all my other females but started to show something. I wish I could attach a picture. My biggest question is when should I begin my flowering stage.

    1. Mark - Sensi Seeds

      Good morning Rich,

      Thanks for your question,
      Great news, that you could remove your male before it pollinates your females.

      Unfortunately, legal restrictions mean we can’t answer grow-related questions or give grow advice on this blog. However, other readers of this blog will often answer questions like yours.

      In general, flowering can usually be controlled very precisely by simply changing the lighting regime. Indoor cannabis growers typically give their plants 18-24 hours of light per day during the vegetative growth period, and drop down to 12 hours to trigger flowering. Indicas will often double in height, and Sativas can often stretch three times there height in vegetation.

      Please check out the following articles on our blog which I think you may find of use, and I hope you continue to enjoy the blog!

      The life cycle of cannabis: From seed to harvest

      How to Flower a Cannabis Plant

      With best wishes,


  4. A co w przypadku jak zacząłem uprawę od czasu 12 h światła 12 h ciemności rośliny nie urosły duże jedna zaczęła kwitnienie wtedy zorientowałem się że powinny dostawać 18 h światła 6 ciemności teraz po ponad miesiącu naprawiłem błąd czy przez to mogę się spodziewać ,że cos będzie nie tak z rośliną?

    1. Mark - Sensi Seeds

      Dzień dobry Marley,

      Dziękuję za pytanie.
      Niestety ograniczenia prawne powodują, że na tym blogu nie możemy odpowiadać na pytania związane z uprawą ani udzielać porad dotyczących uprawy. Jednak inni czytelnicy tego bloga często będą odpowiadać na pytania podobne do twojego. Przepraszam, nie mogę być bardziej pomocny.

      Ogólnie rzecz biorąc, istnieje kilka powodów, dla których rośliny konopi mogą wcześnie zacząć kwitnąć. W większości przypadków rośliny konopi kwitną, ponieważ zostały umieszczone zbyt wcześnie w sezonie, podczas gdy był okres ciemności wystarczająco długi, aby zmusić odmianę do zakwitnięcia. Dramatyczna zmiana w środowisku oświetleniowym może również spowodować zakwitnięcie roślin.

      W miarę wydłużania się dni rośliny mogą powrócić do cyklu wegetacyjnego, a jesienią zakwitnąć normalnie. Jednak niektóre rośliny mogą nadal kwitnąć i nigdy więcej nie wegetować.

      Ten artykuł zatytułowany „The Life cycle of Cannabis: From seed to harvestw” może Cię zainteresować.

      Jeszcze raz dziękujemy za pytanie i mam nadzieję, że blog będzie Ci się nadal podobał.

      Z najlepszymi życzeniami,


  5. Hi! I starts one little seed the last week of January2021.. I live in Phoenix, Az. I planted the seedling in a small pot in my kitchen window on Jan. 30th and have not moved it. It does get 12 hrs of sun and so far it is only about 3 inches tall, but it is flowering. I can already tell that it’s a female. Am I doing everything ok? First time I’ve tried growing. Thank you and stay safe, healthy, calm and peaceful!

    1. Mark - Sensi Seeds

      Good afternoon Sonya,

      Unfortunately, legal restrictions mean we can’t answer grow-related questions or give grow advice on this blog. However, other readers of this blog will often answer questions like yours.

      In general, there are various reasons why cannabis plants may start to flower early. Most often, cannabis plants flower because they were placed out too early in the season, while there was a period of darkness long enough to force the strain into flowering. A dramatic change in the lighting environment could also cause trigger plants into flowering.

      As the days get longer it is possible that plants could go back to vegetative cycle and then flower normally in the fall. However, it is possible that some plants continue to flower and never re-vegetate.

      Please check out the following articles on our blog which I think you may find of use, and I hope you continue to enjoy the blog!

      What are the best conditions for seedlings

      When can seedlings be put under lights or in the sun

      With best wishes,


    2. sonja Herrera

      I have done the same I’m a new to this but I started with seeds and a grow light and now I have 2 12 inch plants and they are doing well

  6. poi pakeha tipene

    Hi mine are all outdoors I’m in NZ I started from seed in October now they are about 4/5 meters tall now and I can’t tell if they male or female they get sun from about 8.30am till about 4.00pm how will I tell if they will show gender or should I wait till about April or May

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    The Sensi Seeds Editorial team has been built throughout our more than 30 years of existence. Our writers and editors include botanists, medical and legal experts as well as renown activists the world over including Lester Grinspoon, Micha Knodt, Robert Connell Clarke, Maurice Veldman, Sebastian Maríncolo, James Burton and Seshata.
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