• Home
  • /How to Sex Marijuana Plants

How to Sex Marijuana Plants

Marijuana Preflowering

Although generally considered one of the trickiest parts of growing your own marijuana, sexing is quite straightforward and will become easier as you gain more experience. The reason for sexing your plants is so that you can remove male plants before they have a chance to pollinate the females. If this occurs the females will start to develop seeds and this will divert their energy from THC production. Pollinated weed is still smokable, we’ve all had weed with seeds, but the potency will be significantly decreased.Careful observation of flowering is the only true way to sex your plants, although you may get a clue from their growth patterns. Male plants tend to be leggier than female plants with a longer internodal length. Female plants are squatter with more leaves and a bushier aspect.Towards the end of the summer, as the hours of daylight decrease, changing light levels will trigger your plants to produce flowers. The appearance of pre-flowers at branch junctions is what you are looking for.Male pre-flowers should be clearly visible to the eye, although a magnifying glass will make your job easier. Male flowers form at the junctions of the branches and stem and the pollen sacs form little balls.How to sex marijuana plantsFemale pre-flowers will also form at the junction of branches and stem and will normally start to form at the fourth or fifth branches up from the base. They are easily distinguished by the appearance of pairs of tiny white hairs, known as pistils.Marijuana PrefloweringAt this stage your plant is just about to enter the flowering phase of growth and now is the time to remove the males if you wish to.


As the plant enters the flowering stage its growth patterns and nutrient requirements will change. The vigorous vegetative growth will slow, stems will elongate and flower formation will begin rapidly at first before slowing. Your plant now needs less nitrogen but more potassium and phosphorous so now is a good time to add some ‘super bloom’ fertilizer. Follow the packet instructions for fruiting or flowering plants.FloweringThe female flowers will start to form kolas around the branch junctions with a main one at the growing tip of the plants. If you look closely you will see the seed pods and these will swell; either with seeds if your plant has been pollinated or with THC as false pods if you have removed the males.KolasAs the flowers become ready for harvest the pistils will darken and the seed pods will be swollen and sticky with resin and THC trichomes.Ready to harvestHowtoGrowMarijuana.com has a wealth of information for growers. We hope you now understand how to sex your marijuana plants. It might be worth reading some of the questions and answers made by our visitors below. 

125 thoughts on “How to Sex Marijuana Plants

  1. atl says:

    this is my first batch im growing outside its only about 4inches out the ground i need this to produce a good crop where do i go from here

  2. downsouthdread says:

    thanks!! for the info im 3weeks inn looking good

  3. small twn says:

    pretty good info!!!!!!

  4. david says:

    now i know .. but my plant is not long or short its kinda stuby ant long at the same time . bow do i know im not waystin my time on a meal plant .

  5. eric easton says:

    at which point do i sex? I am approx at 4 weeks, some are 3 inches, some are 8 inches. Ive seen no evidence of “balls” or “pistals”. Please advise

  6. haffa702 says:

    Last season was ok with these methods”
    This season I have gone step by step and I’m amazed,,
    Realy third season growing and ” I can say second month
    And they are five footers pretty nice ….. Great info : haffa@702

  7. caj says:

    One other question: U don’t get too specific about watering if u have them in pots outside. What is the average # of times per 7 day week?

  8. caj says:

    Wow, my plants are looking so good with your advise. I did top mine because of height restictions and now they are about 25″ tall and full of branches, they are just 6 weeks old and they also smell like good sensimillian.
    Thanks for the info

  9. kushy man says:

    at what time can you sex your plants ? 6 weeks ? 30 weeks ? ??? reply plz

  10. Kashif Khan says:

    Man you are awsome, i have just started growing my babies and they are 6″ tall now, I have 8 pots 1 gallone for each baby on the roof top, I live in India and I have 12hrs of great sunlight and I am hoping to hunt a big bounty.. 🙂 Thanks for all this valuble info..

Leave a Reply

Your email address will not be published. Required fields are marked *


Time limit is exhausted. Please reload CAPTCHA.