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Sexing Your Marijuana Plants – 6 Tips

Sexing Your Marijuana Plants – 6 Tips

One of the most annoying things about growing marijuana is that you have to accurately determine the sex of your 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.

Download my free marijuana grow guide at this link for more growing tips

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.

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. Have a look in our seeds webshop. (We ship to all countries, for free)



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Comment Section

21 thoughts on “Sexing Your Marijuana Plants – 6 Tips

By tamim on 22 May 2013

ian felin wil

By CzarOP on 17 August 2013

2 – Questions

1. What kind of hydrogen exactly do you use to soak seeds before planting?
2. How to choose the best seeds for next season? And details as to how to prep and store them please ?? need these 2 questions answered to complete the jigsaw! Thanks Robert.

By Midowo on 6 September 2013

Great information!
I now can see from the height and how close the inter nodes are who is a male and which are females before even those pre-flowers form!

By Sandra on 19 July 2017

Wats the height that u determined the sex???

By wayde Batchelder on 8 June 2015

Can I put my plants into 36 hours of dark to also sex out

By latewood.ILGM on 7 May 2016


Do not know what you are talking about; “sex out” What?

By david cissney on 6 May 2016

Can you sex a plant by branch formation, male branch’s straight across , and female branch’s offset. Is it true ?

By Joshua on 9 April 2017

No, clones offset. Males and females grow opposite symmetrical shoots. In the late stages of vegetation they will be very slightly offset but this is true of males as well. By slightly I mean about an 1″8 inch or less 2-3mm

By Jessica Amonson on 27 May 2017

Yes it is true. I’ve had %100 success using that method for sexing my plants.

By latewood.ILGM on 7 May 2016

david cissney,

No you cannot. Sex is determined by preflowers only! 🙂

By wes on 9 September 2016

If I touch an unopened pollen sac and then go touch a female plant will it affect it

By Joshua on 9 April 2017

No, you must transfer pollen. To the female. Did you do this on accident?

By Tim on 15 May 2017

What will happen if I put a plant 7 weeks old 12 hours light 12 hours dark

By Bill on 15 May 2017

Your plant will go into flowering.

By Rango on 6 July 2017

Females start flowering as the days get shorter.

By Allainyaha Charlene Matthews on 9 July 2017

If you want seeds but control over how many. Isolate your make of course, DON’T TOP. Use the top to pollinate, your female, cutting it, tie it loosely around the part the female buds of choice to pollinate. COVER with breathable fabric as to not allow the pollen to reach other branches of the plant. This can be very tricky, since pollen can easily get everywhere. But a fun trick try if you attempt a second harvest from your plant. Using the pollen during the second harvest

By Nor CAL/ So cal on 23 July 2017

Yes i have had some very strange things this season.Two different plants both showing female traits for 3 months and in the last two weeks bang they changed – one bush was full with many limbs and the second grew skinny and tall with only two limbs the second of the two may have been heat stressed but not the bushy one. got rid of them both – but check this out to cutting 6 to be exact so far 4 females the other two aren’t showing a thing

By Kirk on 3 September 2017

If I have a male plant do I pull the whole plant out or just cut it off close to the earth. My concern is the roots my be intertwined and damage both plants.

By skooter on 1 February 2018

My recent trainwreck grow hermied but the weed was still potent.

By Bill on 4 March 2018

Yeah, I have to say “skooter”; I’ve had the same experience with hermies. Funny looking flower with alot of punch.

By 2high2grow on 26 March 2018

Helpful! Started with autoflowers and after the next harvest i will try to breed a motherplant to keep cloning! 😀 enjoy your weed my friends

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