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Sexing Your Outdoor Marijuana Plants


The sex of your plants is genetically determined but is also influenced by the environment. The cannabis plant has two pairs of sex chromosomes, one of which carries the genes that determine sex. As with humans, these are either X or Y. Male plants have the XY chromosome while females are XX. In nature, each grouping has a roughly 50:50 chance of occurring per seed, but in your garden you can control male to female ratios once you learn to recognize what each gender looks like.

Identifying Females

Female marijuana flowers, which start to appear later than those of the males, look more like sacks. As they develop, two upraised feather-like stigmas will shoot out of each sack. They are usually white or cream-colored and are generally found on the main stalk at a node region. A node region is the area on a plant where a branch grows from the stem or where a branch grows on a branch. These stalks are designed to trap the pollen released by the male plant and carried along by the wind. Download my free marijuana grow bible to learn more tips and tricks for growing marijuana.

A word about Pollination If a female plant should receive pollen, it will no longer focus its energy on growing flowers, but will instead start to produce seeds. A healthy female plant can produce a lot of seeds, but unless you are trying to breed a particular type of marijuana, seed production will offer you no benefits. For this reason, growers remove male plants as soon as they identify them.

Another reason to remove the males is that this will give your remaining female plants more sun and light, and will also reduce the number of plants you are tending. Male plants are not very good to smoke, but leaving them in the ground (away from your females) is fine, because you can still use the leaves to make potent pot butter.

Identifying Males

Male marijuana plants usually start to flower one to four reeks sooner than females. They develop fewer flowers and tend to grow straight up, with flowers developing near the top. The immature first flowers (preflowers), appear at the tips of the main stem and branches. These flowers are usually closed, green, and develop in tight clusters. The main parts of the male flower are five petal-shaped objects that enclose the sex organs. They look like a tiny bunch of bananas. As it matures, each one of these clusters opens to reveal a stamen. Stamens allow the plants to produce pollen that is used for reproduction in the wild.

The best way to identify a male is by looking at the preflowers, the calyx, during the early stages of growth. If the calyx is raised on a small stalk or stem then it is generally a male. lf the calyx is not raised then it is generally a female. Watch these areas closely as they develop to learn the difference.

Removing males from your Growing Site

Uprooting male plants from the ground is one extremely reliable way to eliminate the males from your crop. Simply remove the plant and the problem is solved. The disadvantage to waiting until the males show flowers at your site is that you may not notice them until they have already released their pollen. Although a female plant can continue to flower while it is producing seeds, only the healthiest ones will succeed at doing both. Download my free marijuana grow bible to learn more tips and tricks for growing marijuana.

Forced Flowering

Another method of growing only females is to screen them when they are very young-before the have been transplanted. This requires forcing them to flower at a young age by controlling their exposure to light but only works with mature plants that are capable of displaying sex.

When your seedlings have grown to about one foot in height they should be mature enough to begin the process of forced flowering. This means systematically depriving them of light for a minimum of 12 hours per day. Soon flowers will have appeared at the nodes, or joints. It should be apparent which flowers are males and which are females.

Remove the male plants, and select the strongest healthy female plants to be transplanted to your growing site. Before moving them outside, give the plants at least three days of continuous light. This will stop the plant from continuing to blossom-you do not want your females flowering too early. Once the plant is outside, receiving the long hours of natural sunlight, it will return to a vegetative state, devoting all of its energy to growing taller and stronger.

Both of the above methods will help you limit the amount of seeds or prevent seed production entirely, as well as reduce or eliminate the presence of male plants however force flowering can sometimes cause sexual dysfunction to appear in plants (the hermaphrodite condition where both sexes appear on the same plant – see next section). Choose whichever method works the best for you, and fits within your time and space needs. The problem is that it won’t completely eliminate the effect of male pollen. In some areas, male hemp plants, growing either naturally or on farms, may pollinate your plants. Pollen has been known to travel many mites from its source (traveling on birds, bees, or the wind) in search of female plants.


marijuana, being a living organism driven to reproduce, may try to reproduce itself in spite of your efforts. In some cases female plants may grow male flowers thereby attempting to pollinate themselves or the plants nearby. Those plants bearing both male and female flowers are called hermaphrodites.

Hermaphrodite plants that self pollinate tend to produce female and more hermaphrodites. Hermaphrodite plants are worth culling. If you must keep the hermaphrodite then picking off the male flower bunches can be one way of limiting the effect and preventing the crop from self pollinating. Hermaphrodites tend to occur naturally as a response to stress when plants are subjected to difficult conditions such as poor nutrients, excessive nitrogen, cold weather, or force flowering.

If you want to start growing, download my free grow guide and order some marijuana seeds. All top quality marijuana seeds are available in my marijuana seed shop. We ship seeds to the US, CA and many other countries. For any growing related question please visit the marijuana support page.

Source: ILoveGrowingMarijuana.Com



About Author

Robert Bergman is a master marijuana grower. Robert Bergman is the author of 'Marijuana Plant Care' and 'The Marijuana Grow Bible'.


  1. My first time growing marijuana. I have 10 plants. Been growing since March. I have watch d carefully for the male plants and pulled any I found.
    I go out to water and inspect my babies and they all are seeding. I am so upset. I live in Tx. My husband has Primary Progressive Multiple Sceloros.
    This was his Meds foe this winter. Now I don’t know what to do.

  2. I’m far from an expert, but given that nobody else has replied I thought I would throw in my limited knowledge. I am pretty certain you have a lady there because
    A) i can see the long pistile coming out the tips of the “balls”. Males don’t have those.
    B) they look furry and sticky wheteas males are ate cleaner looking and
    C) males tend to have there little “balls” on little stems. Yours are growing straight off the plant.
    As I said, I am no expert but until someone more knowledgeable says otherwise, I would assume they are sexy ladies if I were you.

  3. Ide sure hate to start yankin my babies, hoping someone can give me a quick opinion on whether or not they went to seed

  4. A catapilla or something ate one of the leaves the seedling only has one leaf will it stil grow??

  5. Random question. Is a plant showing its sex early a bad thing? Out of my x number of plants, all in full veg, only about a month in, one is showing its sex already. Its still growing in veg forsure, but on my years of doing this ive never had a plant show its sex so early. Only thing im doing new is led instead of hps

  6. Just be careful ! That male tree will leave pollen-dust on your sleeve and may transfer onto your females when you’re working your garden. Make sure you wash hands wear gloves etc..

  7. I have 15 fire OG and 10 forum cut gsc trees that i started from seeds. They are all pretty nice. Waiting impatiently to see which are keepers. I dont wanna force flower. Cant wait!! I hog seeds from some fire i bought off some grower genius. So freakin excited!!

  8. Here’s my last 1, I topped it a few times, and accidentally topped it when transplanting, so it’s way behind where the rest are… this one really scares me, i see the 2 white hairs that a female should produce… but i alsso see that seed sack possibly forming… please help, not just for me, but my neighbors too…. also 1 last question, how along are these plants in flowreing? Ive never grown outside, so this is com0letly new to me… always been good indoors, but that was off clones, and a cntrolled enviroment…

  9. OK it’s late August here in Denver co, here’s what my plants look like, just want a 2nd opinion on their sex, and what nuets should I be using now? Any help is always helpful! Posting 2 of eqch plant… the first one im not sure if its going hermie on me,or its female.. i bought “guaranteed female seeds to start, but being extra cautions i guess before i ruin my crop and they whole neighborhoods plants get scrwwed… also does anyone know how much theyll grow when flowering? Ive read they double in size, not sure about that being indoors, or outdoors… again any comments would be great!
    https://uploads.disquscdn.com/images/8f25c342cc30e735733425be0d3d6dc3a8380f185d076774125072865310725a.jpg https://uploads.disquscdn.com/images/049bc4c066c6cc8f7d3beb32a13e631dde2171f2d9d4d06f09400bb86cf533e0.jpg https://uploads.disquscdn.com/images/7ec8958ff48094e985276a70369450f77ac74fed608fd1a70cbc2312bd8b393b.jpg https://uploads.disquscdn.com/images/2f02b68e2f5dd00aaa35ab5561b34ba486a9943c38b15ee1e6c76ccb0daddf93.jpg https://uploads.disquscdn.com/images/0a202bf9fda83fb7945a16239fe881523f53b40b256886682ba55fd8897e4293.jpg https://uploads.disquscdn.com/images/fbcbac612cccc5d91a3db94a6b7f417fdea1f85e9e4e98605dd680b268a4d0ae.jpg https://uploads.disquscdn.com/images/7c1d0ffd916f1b52c52c124cf31fefcb0cb3de57c9fefff31aa49921ae63b1c2.jpg https://uploads.disquscdn.com/images/cd8e44e72f7b7e5e6f0ea2be87efa502771d79434692b08c680e9c7021c1dc35.jpg https://uploads.disquscdn.com/images/764edc87a0a175295c24ed7d3a7cb0a49389d221c3ec0b56dca77de05c1202b2.jpg https://uploads.disquscdn.com/images/6387738bef004a05f0569ab63249ed01e79b67b6fefb4b398db0798a67ba0d80.jpg https://uploads.disquscdn.com/images/dfd9237a3be8a5d17a3720c3909b6180700954975cf6aed7906ee8754cdcf3c1.jpg

  10. its NOT its not recommended if you dont want seeds in your female plants pollen will survive in the air for up to three days and will get to you females.

  11. Is there a reason my plant is on its forth node and it has a three leaf patter

  12. Sadly that’s not always the case and more importantly different strains grow at different rates but if you’ve been growing 1 strain a while you’re right you can pretty much have a good idea of which will be which by their growth rate and height.

  13. Sadly male plants produce pollen which then floats around impregnating any plants in the area, and it’s a vast amount of pollen so if there are any females in the area they will produce seeds and drop their potency by a ton. So you really have no choice but to pull the male plant if you want the females to bud up without seeds.

  14. Umm pollen doesn’t turn plants male in impregnates them making them produce seeds.

  15. Males pollinate the females which then produce seeds among the buds, which in turn gives you seedy bud :(
    Males do not grow seeds, so that won’t work out to well for you. You can how ever collect some of the pollen from the males and self pollinate a few buds on one of your females, if you are wanting some seeds for next year. If you don’t want to worry about seeding all of your plants its best to cut down the males. Although less known males do in fact contain THC and should be cut dried and placed in the freezer (the whole plant minus the roots) until you have enough plant material to make butter for some yummy edibles.

  16. There is some great info in this. One question: I’ve got a few fems out in my garden and a male in a flower pot about 30 feet away. Can I keep him growing to harvest seeds (to roast and eat — and because it’s super pretty with the other flowers that are planted around it), and if so, how far should he be and does he need to be around a corner or something to keep the wind from pollinating the fems?


  17. o shit my bad. thats weird I wonder why its there now but not the previous time i clickd over to this article. got a little pissed after typing a paragraph only to see “0 comments” when i came back to see if any1 responded.
    btw Gods honest truth about the homless guy and SF dispensaries selling garbage, not medicine.

  18. TWBcensorsreefer on

    there are ways to tell without forcing. i explaind once, but TWB loves erasing my comments, and I really dont have time to double type. why are ppl. in this industry so scared of someone with knowledge?? Im in SF and just bought better medicine from a homeless guy (10$ of icewater hash) than I can find at ANY of the dispensaries in this city. Seems the knowledge I have is intimidating to some who make their living in this industry. Which makes them a few notches lower than an actual prohibitionist. STOP ERASING GOOD COMMENTS; WEED BLOB! If you want the info in the erased comment, read Mel Franks book:The marijuana growers guide.

  19. you can make an educated guess as to the sex of a plant by looking at certain clues. Females tend to grow slower, shorter and bushier with slightly larger leaves than their male counterparts. A female tends to grow a more complex root system before growing fast above ground. A male tends to grow faster from the top shoot. These signs are a good way to make an educated guess without force flowering.

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