Plant sex, predetermined or environmental influenced?

I have been trying to dig up info on this but I never found any that was really credible, just a bunch of bullshit about doing crazy stuff to your plants with no actual experiments or results. (like birth control pills, yea fucking right)


Are there relatively certain ways to tell the sex of a plant before it shows sex on its own?

Like.. taller lanky plants tend to be male.. or...?

My first grow I had 2 plants, one of them smelled like dank, when it was growing it had what looked like trichomes on it when it was about 2 weeks old. The other plant never got the crystally haze on the leaves, and didn't really smell. At about 3 weeks my dank smelling plant got stem rot and ended up dying, so I was left with one plant, which ultimately was a male.


I am punching myself in the nuts for giving a buddy of mine my last bagseed plant that I nurtured for 2 weeks waiting on my feminized seeds. Didn't want to risk root entanglement with a male plant in my DWC setup either. This plant is growing the same way my stem rot plant was growing, I will be able to get clones from it, but no guarantees they will root etc.

Man, I have researched the net and seen so many different ideas on this subject.

Never really found a true answer for it which leads me to believe that it is predetermined. I have also come across several instances where there was mention of a Russian study done that said if you give your seed at least 4 inches of room to develope the tap root then you will have a greater chance of a female plant.

Unfortunately I can't find the study itself!

I still give the seedlings 4 inches and in all honesty I end up with mostly females.

i have had great luck with female ratios as well ,there is no way they are 50/50 i do believe it has to do with conditions greg green in his book says temp.nutrients and stress plays a part in sexing,all i know is im going to keep doing the same thing

robert 14617 said:

i have had great luck with female ratios as well ,there is no way they are 50/50 i do believe it has to do with conditions greg green in his book says temp.nutrients and stress plays a part in sexing,all i know is im going to keep doing the same thing

Click to expand...

Same here.

I have had good luck with females so I don't change a damn thing with what I am doing. I could not tell you what I am doing right or wrong, I just know what works for me.

Yea, the plant that ended up male on my first grow went through some major stress, and that's what I attributed its sex to, but now IDK.

So far my ratio is 100% male.

But genetically, does the seed have xx or xy chromosomes? or are those created after germination...? after it sprouts?

What do you mean by 4 inches? A 4" long taproot? or the spacing in the germination 'medium' (paper towel, rockwool w/e)?

The 4" meant give the plant at least 4" of depth for the tap root to develope.

See, I actually germ my plants in Jiffy Pucks and plant them into 3 gallon buckets. So they have plenty of space to dig as far down as they want to. I have read and seen a lot of people growing their seedling in little plastic cups and tiny clay pots and then waiting too long to tranplant. So the taproot (main root) can't grow any farther down than 2-3 inches.

I guess the idea is to give them as much root space at the beginning and somehow it contributes to determining the sex.
Like right now, I have my plants in the 3 gallon buckets and one of them cracked so I had to put it in a new one. Well they were about 3 weeks when this happened and the roots were already at the bottom and the bucket itself is 12" tall.

So within 3 weeks the roots grew to a depth of about 1 foot. Now the plants are 5 weeks old and I am fairly positive that it is a female.

I am a strict hydro/aero grower, so my roots just grow out of the hole I cut in the bottom of my medium into my reservoir.

I tend to sow my seeds pretty high up in the sponge though, maybe 1/8" from the top. They seem to sprout real quick that way.

i've read about male and female hermi i would almost bet they carry both sets in some seeds like alligator embryo's they don't sex until they reach a certain stage in development and the trigger is temp

That sounds logical...

Temp is the only factor that sounded reasonable in most of the posts/articles I came across.

Plants can show sex in veg sometimes, right? (under normal lighting conditions)

but what about autoflowering strains?



My plants went through some major heat / moisture stress really early on, when I only had one true node, and the leaves started curling under, had to bitch my roommate out for turning the heater on 80 degrees when it was 74 outside. After that hiccup the plant was looking like a champ (see my avatar)

i had a problem early on i over watered during seedling stage they stressed a great deal and were slow to start growing after about six weeks they got back on track the worst stressed plant wound up being male ,the male has longer spacing between nodes

From literature and our own findings it appears that the growth of a male or female plant from seed, except for the predisposition in the gender chromosomes, also depends on various environmental factors. The environmental factors that influence gender are:

• a higher nitrogen concentration will give more females.
• a higher potassium concentration will give more males.
• a higher humidity will give more females.
• a lower temperature will give more females.
• more blue light will give more females.
• Fewer hours of light will give more females

Not sure how accurate this is it’s from http://www.dutch-passion.nl/home.php?l=en&p=feminized


Hope it helps