How to distinguish marijuana males from females

How to distinguish males from females in cannabis growing

Marijuana (cannabis sativa sp.) is a dioecious or unisexual plant, what means that it produces male and female flowers in different individuals, although we can find both types of flowers in hermaphrodite plants. We call males those plants that produce male flowers, and females those producing female flowers.

Male and female cannabis flowers

Male and female cannabis flowers

Marijuana males flower producing small bell-shaped clusters, that hang down and open releasing the pollen, while females produce tear-shaped calyxes with two pistils – usually white – that group together forming what we call buds.

When to determine the sex of marijuana plants?

Male and female cannabis plants

Male and female cannabis plants

Generally, cannabis plants start flowering when nights – dark periods – are longer, which is a sign to show their sex and start blooming. Actually, marijuana plants reach their sexual maturity between 6-8 weeks after seed germination , regardless of the photoperiod.

It is this fact what can help us to determine the sex of our marijuana plants without the need to make cuttings or change the photoperiod, what could strees our young plants.

As we mentioned before, when plants are about 2 months old – when they have 5 or 6 internodes – they are sexually mature, which is to say, they have set their sex. In some cases – most of them produced by stress – plants will show both sexes, being what we call hermaphrodites, but generally at this moment plants show their true sex, that will mantain for their entire life cycle.

This technique of premature detection of the sex needs a little practice, but once mastered it will allow us to determine the sex of our cannabis plants at a very early stage.

Sexing marijuana from cuttings

Early flowering of a female cannabis plant

Early flowering of a female cannabis plant

If we can’t sex our plants with this technique, we can take a cutting from each of our marijuana plants and flower it in a growing tent – 12 hours of light/darkness photoperiod – what will force it to flower and show its sex, that will be exactly the same as its mother plant.

What we don’t recommend at all is forcing the flowernig of mother plants for a few days/weeks and once they show their sex placing them again with a growing photoperiod (18 hours of light/6 hours of darkness), since this will produce major hormonal changes inside the plants, being an easy way to stress them – what will improve the chances to get hermaphrodite plants.

Male marijuana plant

Male marijuana plant

July 24, 2014 | Cannabis grow guide
28 Comments


28 comments on “How to distinguish marijuana males from females

  1. agi

    Can I grow about 4 plants in one pot and when flowering if I come across any male plant can I just remove a male. And is 2 125wats CFL ok for 4 plants

    1. Dani Alchimia Post author

      Hi agi,

      The roots of the plants need as much space as possible to grow, that’s why we normally use one pot per plant. You can do as you say without problem, but try to use a large pot so that once you remove the males your females have enough space to grow.

      About CFL’s: 2x125W is ok, but do not expect the same results than when using an HPS lighting system. With two CFL you’ll have enough light to cover a 1m2 area, but as I said you won’t have the same results as if you were using, for example, a 600w HPS.

      Hope it helped!

  2. Ginger Garrett

    It was is the middle of july in Sacramento Ca. Should i change my feeding my plants for flowering now till Oct. And will they grow. Bigger? They are in 27 gallon pots with about 3 to 4 ft tall.

    1. Dani Alchimia Post author

      Hi Ginger,

      You should start using nutrients for Bloom as soon as you see the first tiny buds developing. Depending on the strain, it’ll stretch more or less before starting to bloom (Sativas normally stretch much more than Indicas).

      Hope it helped!

  3. Left Coast

    I want to veg my outdoor longer but they are starting to show some flowers. Any recommendation on what I could I use to stimulate rapid growth to make them hold off on blooming?

    1. Dani Alchimia Post author

      Hi Left Coast,

      You should use some light source at nights to “break” the dark period of the plants. If you light your plants after 3-4 hours of darkness for around 30 minutes you’re breaking the bloom photoperiod, so your plants should keep on growing until you remove that light source. Some growers use different schedules, like turning on the lights every 45 minutes for 15 minutes during the night.

      Hope it helped!

  4. Kevin

    I have a beautiful plant that is flowering and am almost positive it’s a female but today while I was looking my plant over I found what I thought was the beginning of a seed pod? My plant looks exactly like the one on this page where it says sexing your plants from cuttings . it is outside and this is my first rodeo so my question is.
    Is it possible that it’s both sexes and what should I do!?
    Also I have another one 5 foot away from is it possible to stop from being pollinated?

    1. Dani Alchimia Post author

      Hi Kevin,

      Hermaphrodite plants show both sexes in the same plant, and often pollinate other plants around them. You can find female plants that develop few male flowers during bloom, which is often no problem at all (we’d be speaking about 1-5% male flowers). But you can also find true hermies, which develop lots of male flowers and can easily pollinate other plants (furthermore, their offspring is likely to be hermie too). If your plant really develops both types of flowers, I’m afraid the only option is to chop it asap, otherwise you’ll end up with a fully seeded hermie plant, and your other plant will be also pollinated.

      Hope it helped!

  5. mark holden

    I’ve got eight plants going one, unfortunately my biggest turned Hermie, it only showed pods for a couple of days before I noticed, I took it down immidiatly will this mess up the rest defiantly or is there any chance for some????? This is an outdoor grow

    1. Dani Alchimia Post author

      Hi mark,

      From what you say, the rest of your plants should be OK, pollen sacks need some days to release pollen. Were the pods open? Unless you had lots of sack open, I wouldn’t worry about it, especially because you removed the pollen source (the hermie plant). If you have plants from the same strain that hermied, keep a close eye on them!

      Best!

  6. mark holden

    Thanks dani you have given me hope, after reading yor sexing tips which I really wished I had I now think another is beginning to herm too, oh well, do you have any tips on what I should do with my cut down males??? Is there any thing that isn’t a waste???

    1. Dani Alchimia Post author

      Hi Mark,

      You can try to juice the leaves or use them to make vermicompost. Apart from that, I’m afraid there aren’t much more options.

      Hope it helped!

  7. chris

    hello quick question. one of my branches broke I have tied it back up to support the break but I was wondering if it will turn the plant male cheers

    1. Dani Alchimia Post author

      Hi Chris,

      That would be really unlikely, that branch will either die or keep on growing, but I’ve never seen male flowers developing from broken branches.

      All the best!

  8. Peymannn

    More help for male and female plant

  9. Koren55

    What’s wrong if a female plant gets pollinated?

    Will the quality go down?
    What about THC/CBD content?
    Would the seeds be viable?

    Just wondering. I live in a rural area, and am wondering about wild weed or other neighbors plants.

    1. Dani Alchimia Post author

      Hi Koren55,

      Normally, when a female plant gets pollinated is produces less cannabinoids and terpenes, since it focuses on producing seed. So yes, the quality of sinsemilla is always higher than that of seeded plants. The seeds will be viable if you harvest them when they’re ripe, but:

      -If the pollen comes from a male, you’ll find females and males in the offspring of those seeds
      -If the pollen comes from hermie plants, you’ll find hermie plants in the offspring
      -if the pollen comes from reversed females, you’ll only find females in the offspring

      Hope it helped!

  10. Robert Cardy

    Hi i dont grow alot and only naturally in the garden i have a critical auto and is doing nicely has about 2 weeks left and has started to produce pods at the base of each flower what should i do if someone has some advice i would be grateful many thanks.

    1. Dani Alchimia Post author

      Hi Robert,

      If it is developing pollen sacks at the base of each and every flower, I’m affraid your plant will be completely seeded at the end of its life. You can try to remove the pods and check regularly if the plant produces some more, which you should also remove asap. But there’s not much you can do if your plant is hermaphrodite.

      Hope it helped!

  11. benny

    I got 3 plants in the ground i have an issue that it might be turning male its been growing since march would like some input on why its looking like some branches of it have seed looking sacks on it

    1. Dani Alchimia Post author

      Hi benny,

      It’s important to know if your plants are females (they have buds formed by white hairs), hermaphrodites (they have both buds and pollen sacks) or males (they only have pollen sacks). Only the first two cases can be seeded. If they are males (they also produce sacks and no hairs) you should remove them asap (also if they’re hermaphrodites). Do your plants have both types of flower (hairs and sacks)? What’s inside the sacks of your plants? Seed embryos or pollen grains?

      Best!

  12. benny

    Not real sure its been raining last few days i do see bud flowers starting at the top but on a branch in the back of the plant has those sacks if possible i will try and upload a pic of what im trying to explain

    1. Dani Alchimia Post author

      Hi benny,

      Sometimes, plants only develop pollen sacks on the lower parts, or just in some branches. If that’s the case, simply remove any part of the plant with sacks and continue checking for new ones regularly.

      Best!

  13. benny

    Oh so just prune those branches out and i did get pics of them but i cant load them on here

    1. Dani Alchimia Post author

      Hi benny,

      Sorry for that, you can send the pics to dani@alchimiaweb.com

      😉

  14. benny

    Ok i sent u some pics of the plant

  15. john tan nguyen

    we need to dip the marijuana before it goes into the dispensary. once it is dipped everything will be okay. no more labs. its not okay.
    stop extracting. just dip it so we can take a new step. once it is dipped the step will be available. pcp then ill let you know what angel dust is.

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