6 Tips for Sexing Your Marijuana Plants

By Robert Bergman, ILoveGrowingMarijuana.com

One of the most annoying things about growing marijuana is that you have to accurately determine the sex of your plant.plant Many growers want to keep their female plants from being fertilized because it is the only way to ensure sinsemilla buds. These buds don’t have seeds and they will have ample THC by the time the harvest comes around. Even then, many marijuana growers just like to get the males out of the garden because they don’t produce that much THC. Determining the sex takes a subtle attention to detail and quick action. Below are a few tips for sexing marijuana plants.

1. 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 you 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).

2. Males mature faster than females. This is one of the most common ways to determine sex on sight. Males will generally reach sexual maturity about two weeks before females. The males will start to grow rapidly and they will be taller than their female counterparts. They will also have these “false buds” which are actually pollen sacs. The reason the males grow taller is so that the pollen can drop down on to the female reproductive organs. This occurs whether you’re growing marijuana indoors or outdoors.

3. Males have flowers, females have pistils. Obviously, 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. Those false-bud, pollen sacs will eventually open up to form little yellow or white flowers. Any female plants will not have these. Instead, they will have hairy, whitish pistils that will be sticky enough to trap the pollen dropped from those flowers. If you wait this long to identify the sex of your marijuana plants, then it’s probably too late to get any sinsemilla buds. Even so, you can still remove the male plants to make room for the continued growth and cultivation of the female plants.

Male marijuana plant.
Female marijuana plant.
Hermaprodite marijuana plant

4. Clone the marijuana plants to determine sex. This is really the only foolproof way to determine the sex before the plants achieve maturity. You simply have to take a cutting from any number of 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.

5. Identify where the plant sprouted during germination. Although it might seem a little strange, 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.

6. Sometimes, you’ll have hermaphrodites. Growers can occasionally end up with some hermaphrodites which are basically plants that exhibit both male and female reproductive capacities. These can be difficult to determine right away because they can send you mixed signals. Hermaphrodites can also come about as a result of environmental stress, making their sex increasingly hard to determine. If you start to notice flowers and pistils on the same plant, try pruning off the flowers to ensure that the marijuana plant doesn’t self-pollinate (or pollinate other surrounding females). Read more about male, female and hermaphrodite marijuana plants.

Have you had any strange or successful experiences with sexing your marijuana plants? Let us know in the comments below. Also, let your friends in one these details by sharing the article on Facebook, Google+ or Twitter.


Last thing: if you buy feminised marijuana seeds, you do not have to sex them at all. No weeding out male plants.


94 thoughts on “6 Tips for Sexing Your Marijuana Plants”

  1. I have a similar plant from seed, it made 3 leaves around the 5th set…now making 4 at once! This 3 week old plant just graduated to a 3 gal pot. I can’t wait to see what happens next. Also hope it’s a girl. I have pix too

  2. What is it that actually marks the beginning of the flowering phase?

    Like, does the flowering phase “officially” start as soon as you can determine the plant’s sex?

    First time grower, outdoors, trying to figure out how many weeks they’ve been in flower (I know I figured out the sex almost exactly eight weeks ago, before any real flowers or buds had formed).

    • Virtually all plants will show pre-flowers as they mature whether they are on a 16-8 or 24-0 veg cycle. This does not mean that the plants are beginning to flower.

      • 16/8 is also a common time variation (the decrease in light is believed to be an environmental factor that favors an outcome of a female plant; during the time plants mature beyond their seedling cotyledon, which are not real leaves, and until the time they have 3-4 sets of leaves, these environmental factors contribute to Females: lower temps, higher humidity, lower light volume (nearer to 14 hrs) and higher Nitrogen levels.. the reverse for all favoring male plants; note: as opposed to Nitrogen, Phosphorous is it’s polar nutrient!).

  3. I have a plant that has three leaves are stems instead of 2 alternating on the stock is there something wrong with my plant.

    • This is a genetic abnormality. I don’t know where you got your plant from but I would waste my time with a plant like that. Those sort of abnormalities are a sign of poor breeding.

    • Actually Steve you are wrong not to put valued time into it. Troy the mutation is actually quite exciting.. at this point you have no doubt forgotten all about this. It’s called whorled phyllotaxy, and almost always produces a much much larger yield. If you are breeding and cross straining, the mutation will no doubt lack the ability to sustain. Though it would have been a great harvest if you kept it Troy.

  4. If you run your light cycle on 12 hrs, off 5 1/2 hrs, on 1 hr, off 5 1/2, it will show the sex but will not flower. Cannabis will grow well with this lighting schedule. It needs 12 uninterrupted hours of darkness for flowering so when you’re ready to flower it, just flip that one hr on to off so it will be 12/12. This schedule saves on electricity.

  5. I think I got a bitch it’s been a month and a half short with all branches on every node connection six. To be exact but I don’t count the small newbies which is just two nodes female??

    Hydroponic deep water culture under 400 w metal halide

    15 hrs light

    Idk if those effect anything but I’m sure it plays a role in size and shape I know it was a bottom germination of the seed

  6. I have never grow a plant before now I have one that is about 1 1/2 months old. It got dropped off a table but I was able to keep it alive. It has 2 roles of leaves now but it is still short. Does any one know if I have hurt the plant to were it may not bud?

    • If your plant is being held together by a bandaid it could make it, I broke a the base of a large lower branch last year right as I started the flowering on my 8 ft white widow (outdoor in big pots here in Oregon it’s legal), I taped it up (was held together by some skin) and it finished out the season and had giant buds like the rest of the plant.
      On the other hand, with such a small plant, it may hermaphrodite or not make it at all.
      Everyone’s a pot expert, my recommendation, make sure you’re giving it a high quality feeding program. Fox Farms is good I don’t like it, I use Botanicare and Greenfuse. It will blow your mind how fast these plants grow if they’re not lacking any nutrients.
      If it’s a female, and it keeps growing, it will flower. You can’t stop them from doing that. Keep an eye out for little flowers appearing.

      In my experience and everyone I deal withs, anytime you force flower a plant to determine sex, then force back to vegetative, the end resulting medicine is never as good.

    • If your plant is being held together by a bandaid it could make it, I broke a the base of a large lower branch last year right as I started the flowering on my 8 ft white widow (outdoor in big pots here in Oregon it’s legal), I taped it up (was held together by some skin) and it finished out the season and had giant buds like the rest of the plant.
      On the other hand, with such a small plant, it may hermaphrodite or not make it at all.
      Everyone’s a pot expert, my recommendation, make sure you’re giving it a high quality feeding program. Fox Farms is good I don’t like it, I use Botanicare and Greenfuse. It will blow your mind how fast these plants grow if they’re not lacking any nutrients.
      If it’s a female, and it keeps growing, it will flower. You can’t stop them from doing that. Keep an eye out for little flowers appearing.

      In my experience and everyone I deal withs, anytime you force flower a plant to determine sex, then force back to vegetative, the end resulting medicine is never as good.

  7. I have never grow a plant before and for some odd reason I have a plant that is about a month and a half old. It has been broke do to it falling one I put a kinda bandaid on it and it still grow. It has 2 roles of leaves on it but I don’t know if it will get taller I am worried when it fall if I stunted the plant. Do you think I have hurt it some how? Sorry if this is a stuppied question

  8. Is it true that the faster and taller plants grow they are most likely male?? My uncle planted eight seeds less than two weeks ago and seven of them sprouted and are now in the seedling stage. 5 of the seven grew fast and are quite taller than the other two. One did not sprout until a week after the other ones. It looks like a runt and has a white spot on one of the leaves. Hmmmm…any suggestions would greatly appreciated=)

    • Lol.. Plants dont turn male if lights fale.. U can just send it into early flowering. The sex is already determined.

  9. Anyone force floweing b to identify females then immediately put the females back into the veg tent to get bigger first??? That possible? Thanks in advance everyone!

  10. years ago i grew 1 feminized indica, and a normal afgani 1 plant ,after 4 or 5 weeks of veg, on to 12/22, the feminized showed sex in a week, the afgan 1 went 4 weeks with no sign of sex. i just left it in and hoped for the best. i had to get rid of both due to scared of gettin busted . but after 4.5 weeks the afgan 1 never showed any signs. i used to grow a lot and i know what to look for. is there a reason for this. if the conditions, heat, cold nutes were off both plants would have been goofy right. the feminized was budding hard and looked awesome. it even had a pretty good buzz for bein half done lol. i was and am still puzzled. wish i could of left it go and saw what happened. my timer was as close to 12/12 as i could get it. 11hrs, 55min on / 12hrs 05 min off time. they were in a grow tent in a closet. temps were like never over 85 at the top nearest the 400 w bulb. ph was always 6-7 and ntes were general hydroponics, with the suggested bloom ratio on bottles. S wtf was up. it sort of drove me nuts every day combing each bud site for sex signs.

  11. I topped my plant 2 Days ago and I noticed few little yellow flower sprout out where I topped my plant is its normal after 28 days from seed they show sex and I think its à hermaphodite because i saw few white hair and few flower didnt opened yet

  12. So can I have my seed starts under light 24 hrs for about 3 wks. Can I put them in 12 1/2 hours of light with out them triggering? They are 5 in now..
    I want to put out side in green house with no lights?

    • 12/12 will make them flower at about 2 weeks of 12/12. when 14 or less hours of light occurs (lights or sun) they will flower

      • thats part of learning and looking for the signs, get yourself a book, marijuana bible, read it study it and start growing, there is a lot more to know than male female, and if you dont know get a book and read and study it !!

  13. I need help determining the sex before I trash …. Can I send a pic to anyone who might be Able to help out..? This is my 2nd “feminized” seed that also seems to be male… Wtf.

    • Come on now guys there’s no dumb question it’s very rude to answer the way you have.think of it this way you guys had to be told once

      • It’s a coin flip whether any plant will be male or female. Growing only one plant will pretty much ensure that you don’t end up with a pollinated female full of seeds, but that’s all.

        If I want one plant, I plant two to pretty much ensure one will be a female. It’s easy to be wrong with just two though. Most would plant five or six, wait until they know which ones are female, and then pick the strongest.

        An easy solution for new growers is to buy feminized seeds. These are guaranteed to be female. They cost more, but you don’t end up with males; so the price evens out.

        For a brand-new guy, I would recommend feminized seeds of the auto-flowering variety. Plant them in a pot that is one third worm castings (buy it on amazon), and you really don’t need all the nutrients all the pseudo-intellectuals go nuts over.

      • Exactly, it’s all new, none of it makes sense at first, and dammit when you started you didn’t know either. So stop waiting for a newbie question so you can feel smart. Answer the question, or shut up and let someone else answer. Some people have lives and.can’t spend days at a time reading through your “witty responses” in order to get real info.

    • I am starting out also , but you’ll have to wait and see! basically the male develops faster and is taller and has pollen sacks , a female develops hair like receptacles from the buds. and even if you remove the males, there is still a chance of fertilization from your dopey neighbor that let his male grow next door. probably a long shot though.

  14. doing my first grow and have a cuple questions. First is I have a seedling that was germinated with my other plants. This one seedling hasn’t grown past the first 2 seed leafs but has 2 small white hairs coming out of th very top right between the 2 leaves. Does anyone know what this means? My second question is how long before I can tell the sex of the plants?

  15. I have a hash plant hybrid, herijuana actually. It has formed a huge lower branch that is nearly the diameter of the main trunk and growing rapidly .it appears to be a separate cola ? Anyone ever experience anything similar? And I’m considering an attempt to cut and clone it ?

    • I have experienced this once, in this last season actually. although i am not sure what caused it, the plant was female the branch was too so its not like it was a danger to the plant as far as being a hermaphrodite branch would have been. i let it grow and it ended up looking like ground cover because it grown towards the bottom and out about half the height of the plant its self maybe a bit more parallel to the ground. its possible that at some point during the flowering process the plant needed more light than it was getting and so it extended a branch to help get more light, it could have been the plant hit a natural nitrogen source but it was only enough to cause one limb to shoot out, it could be do to genetics. (in which cause a clone would do the same thing since they are both exactly the same plant) as long as it doesn’t seem harmful it should be fine, just know that in the possibility that its a genetic thing that all of your clones are going to do the exact same thing which may or may not be a bad thing. that’s up to opinion.

      • I think if you bend them(not break) and more light hits the side of the plant(more plant exposed) from the overhead light it produces several colas instead of growing the plant upright.

    • Hermies do that we had an opp a few years ago that did that in one side ended up jut covering plant and cutting off pollen sack without opening or puncturing them

  16. People discard the males right away. I think that is a waste. Today’s weed is so strong that even the males are good if you catch the bud before it flowers. I found that 3 minutes in the toaster oven and then straight in the bowl works out just fine.

  17. If I send a pic to someone can you tell me if it’s a boy or girl? I see a lot of people asking and my plant is very tall and sparse. I’m thinking boy but it I trash it befor I know for sure I’ll never stop thinking about it. I just can’t live like that.

    • Sue, if you see things that look like little bananas, it’s a boy. If it has hairy buds, and bananas, it’s hermaphrodite. All hairy buds and no bananas it’s a girl, for now. If you stress them, they will think the world is coming to an end and make their own male flowers.
      Even male buds can be smoked if you catch them before they open. Just keep an eye on them or the girls will be nothing but seed.

    • Try putting cogs butts in a spray bottle and giving your plant a really light mist. It won’t bother the plant too much but nicotine causes almost instantaneous heart failure in small insects.

    • Big Time Exterminator. It’s all natural, works well. No need for a flush in your plants, and is effective. Kleen Green and Tweetment (as weird as their names are…) both make for great preventative measures. Foliage once a week under the leaves. Only foliage in flower for first two weeks. Clean your tent(s) with either of them after each cycle. Stay consistent with the preventatives, and you should be just fine. I live in the mountains about 50 yards from a river and no bugs, yet. Hope this helps. 100% organic should be your goal. Think about it… If you’re not willing to eat or drink it yourself. Why would you give it to something that you will, eat, smoke, or use as topical, later? Buildasoil.com is a great place to get all of your growing needs, in ONE website.

  18. I have 6 plants all about 3 months old and cant tell the sex can i send someone pics so u can help me out please let me know

    • You sex your plants when you flower them. Put your lights on for 12 hours and off for 12 hours. Within a week, you should be able to see the sex. With some plants, (none that I have grown), you may have to use less than 12 hours of light per day.

    • colloidial silver. At about 40ppm. Spray the plant daily starting when you switch to 12/12. It will chemically hermy the plant. When both parents are female the seeds are about 95% female. If you stress them into hermy or if you let them go to the bitter end an sprout a few pollen sacks but that tends to bring out the hermy trait in the offspring.

  19. I have like 6 lil plants, but i cant determin if there male kr female.. I planted them like 5 weeks ago… Can i send u some pics so u can tell me?…

  20. Mine are weird but it is my first time. The tall one seams to be female and the short fat one looks like a male. Can I email a pic to someone to help me out?

  21. Found two ball on my plant that is budding pretty good, is it possible to remove them. Would that prevent it from pollinating itself.

    • Yes if you do not puncture or open the sack also you can buy a solution you spread on the female flowers to keep them from pollinating

    • 8 To 12 weeks depending on conditions, my friend also grows widow and his last crop took 13weeks of flower. ive managed to get mine down to 8weeks now with doing my research 🙂

      • There are a few places that say White Widow can finish in 8 weeks, but almost always that comes from someone who is selling the seed and not someone who is using the seed. If you can finish them in 8, please let the rest of the world know what you are doing.

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