Why are my plants turning male?

What determines the sex ? I started my seeds like always with the paper towel method of germinating. I normally have a ratio of about 60%-70% female to male. This year I started 15 plants, and after 1 month 13 turned male ! What gives ? I used same seeds from last year, and did nothing different. We were hit with an unseasonal cold front, could that have been a factor ? Are the sexes pre-determined, or are there other factors at work ? Now I have to start over, and a month behind ! At a loss

Stress can cause a plant to herme, but it sounds like your plants got pollinated

Perhaps you just picked the wrong seeds this time.

What light schedule are you on? Usually photo plants won’t show Sex until you flip the lights below 14hours of light.


If these seeds are regular seeds, meaning the are not feminized, then the ratio is about 50/50. In other words toss of the coin. The fact you did better before has no real bearing.
Yes, seed sex is already determined. However, stress on a female plant can cause it to hermi and as a result a female can grow pollen sacks like a male. Still a female, but likelihood of seeds to hermi goes way up with resulting seeds.


Whatever mother nature throws at me, Outdoor grow. That’s why I’m thinking the cold did it. Yeah , they don’t usually show sex until after a few months

How can they be pollinated before they have buds ? I thought a male
pollinates a female ? I have had herms before. Is that what you mean ?

It used to be thought that environmental factors could turn a seed destined to be a female into a male.

According to the latest books I have read this is false.

The issue you are having is sample size. If you were to germinate 1000 sears you would see something closer to 50/50 ratio.

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OK So I did nothing wrong other than pick the wrong seeds ? They were males from the get go ? That makes me feel better, thought I did something wrong. I have limited space so I germ. small batches , as to not end up with 20 females at a time. Would be hard to dispose of a female, and could lead to my " un-doing "( not a legal state )

In my opinion, yes.

This might be helpful when picking which seeds to plant.

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That is just AWESOME ! That is the coolest thing ever. First time ever hearing that you could tell sex by just looking at seed. I have always picked the biggest, darkest, ones, or ones with the most " tiger stripes " . THANK YOU ! You learn something new every day. You are the man !

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You can’t tell from the seeds @Reticence is correct it’s a 50/50 chance you just got lucky last time with more female and this year you wasn’t so lucky!!! Hope this helps!! Happy growing and best of luck

Try femimized seeds, next time.


Shindig seems pretty confident, 100%, bold statement . Never heard that before, maybe that’s why.

If I remember correctly the article stating that pic is false it’s not even cannabis seeds that or shown in the picture not saying it’s not but there is so much disinformation out there it’s hard to know what is real or not.

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A few people have tested that chart. If you look around, you might be able to find those threads. :grinning: Consensus seems to be it’s not really accurate.

I tested it on bag seeds. It was 100% accurate…except all the females ended up being hermies. Lol! So, in the end, it really didn’t help at all. Now, I just buy feminized seeds. If I grew photos, I’d clone.

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Chart isn’t 100% accurate. I pulled 10 seeds should’ve been male, I think 8 female two male.

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Kinda blows that theory all to hell huh


OK, I picked out a dozen that should have been female, and 8 female to 4 male. But I think it’s like Iv’e heard a 50 / 50 chance. On to the next question, is there a better time of day to transplant from small to large pots ? I notice they droop a little at dusk , at night , so got me wondering about this . ( outdoor )

You know, I’m not 100% sure. I don’t grow outdoors other than veggies that go straight into dirt. But I would say near end of light period seems logical. Would give them some time to recover before being blasted by sun anyway.