Early Sexing

[pinecone]

I occasionally see threads where growers consider throwing plants into flower or cloning and flowering just to determine sex. This has always seemed silly to me as (with the aid of a jeweler's loop) I have been able to determine the sex of most well cared for cannabis plants by the time they are a month old (from sprout), and before they are really large enough to take cuts from.

Pine

You need a jeweler' loop


Below are 3 SSH seedlings just starting to show their sex. They were sowed on February 25th, 2011 and sprouted 4-7 days later. The picture is from today so they are 3 weeks or so from sprout. They have been are in 16oz cups and under T5 HO (6500K) lighting on an 18-6 schedule. The plant on the left is a female, the one is the middle is a male, and the sex of the one on the right cannot be determined yet (it was the last to sprout and is a bit behind the other two). I expect to be able to sex this last plant within a week.

Nodal region on the female plant. Note the long slender shape and smooth texture of the preflower. Even if you couldn't see the hairs this shape and texture would be an early indication of a female plant. I find that hairs are typically visible through a loop shortly after a pre-flower is visiable to the naked eye, but sometimes the the first few female looking preflowers don't show hairs right away. In these instances the first hairs usually show on preflowers forming on upper nodes.

Nodal region on the male plant. Note the difference from the shape and texture of the female pre-flowers.

 

[Maj.PotHead]

thats nice but the erea ya highlited isnt a preflower they'll show preflowers right next to the stuplia many moons ago that was a thorne. but over time and evolution it became soft

 

[pinecone]

thats nice but the erea ya highlited isnt a preflower they'll show preflowers right next to the stuplia many moons ago that was a thorne. but over time and evolution it became soft

The preflowers are most definitely in the areas that I highlighted. They are right next to the stuplia (or whatever you call them).

Pine

 

[Budley Doright]

Those structures are called stipules...

And indeed preflowers form behind them.....


looks like females top and male below..


By the way you can remove the stipules for a better look at the preflowers....


just grap it with tweezers and pull down....


I do it all the time...


By the way I wrote a thread on early sexing on OG....


I used to say look for preflowers the node below the top node....


right where you are looking....


I didnt see you had already sexed them ....sorry.....


one thing to note about tiny female preflowers....


the very tip is a darker green....


male flower its normally lighter on the top.....

 

[Shcrews]

for easy sexing, i prefer tequila, MDMA, or any combination thereof

 

[pinecone]

The last one showed its sex today. It is a female.

Pine

 

[rrog]

It's a little hard for me to see, but you mention the pre-flower shape is different as well as the texture. Male = sphere female = pear shape. When I've tried just using that as a barometer, they all look like they might go either way... that's my untrained eye, obviously.

Burnt Rope introduces something new for me... the darker green tops of female pre-flowers.

The texture thing is new to me. Females are smoother?

 

[pinecone]

The males almost look like little short lobster claws to me (at least initially) whereas the females are smoother, longer, and pear shaped.

Pine

 

[rrog]

Thanks so much for taking the time to post this. Very helpful.

 

[yesum]

This may be worthy of sticky? Thanks for the info and pics. I am vegging in party cups and plan to sex the plants in the cups and then up pot the females only. Will save a bunch of soil and space.

 

[dancingroots]

good stuff!

 

[GoneRooty]

Great thread Pine! It always annoys me when people say, "oh just throw it into flower for like a week or 2 and it will show it's sex" Cannabis doesn't show it's sex until sexual maturity, usually about 4weeks after sprouting. So if you sprout seeds, and then 2 weeks later throw them into flowering, and have to wait 2 weeks for the flowers to show, you're still at the 4 week sexual maturity mark. Just leave your plants in veg until they show preflowers, less stress for the plant from going from veg to flower and back to veg.
Also, if your seedlings aren't at sexual maturity and you throw them into flowering (under HPS with more red spectrum) you stand a chance of getting more males, since light spectrum is one of the variables when trying to get more females than males. Or am I mixed up on the light spectrum thing?

 

[vonforne]

Damn pine......you need to use some hand creme. lol and a manicure.

Nice thread BTW.

V

 

[habeeb]

not, sure, but I'll say my experience

-pre-flowering shows at the 5 node, this is not dependent on time, just growth/maturity, as a plant can grow faster if you give it optimum environment. I've seen some show on 4th but its rare

-I see it backwards then you guys. the females are spear shaped, the males are alot rounder, also another sure fire is females are smaller and stay closer to the node, while males are bigger, and you should already be able to see a small stem on them, if you look with a loop, and not be as tucked in as the female..

-males are usually the taller plants

-males usually show before females, about a 1-2 days before usually

 

[vonforne]

To me it is strain dependent. I have a Thai that is almost impossible to tell sex for at least 10 weeks.

And then I have some indie dominant strains that indicate sex at 3 to 4 weeks like Pine is doing.

V

 

[pinecone]

Damn pine......you need to use some hand creme. lol and a manicure.

During the long dry winter we get "ashy".

this is not dependent on time, just growth/maturity

Given normal growth rates time and maturity are related. I've had burned or otherwise poorly treated seedlings that have taken much longer to sex, but I attribute this to grower error. I've also had exceptionally slow growing or mutated plants (blue-thai type crinkle leaf mutations) that did not show in the normal amount of time.

To me it is strain dependent.

I'm not sure about land race sativas because I haven't really grown any, but I have grown a bunch of sativas, and the vast majority show their sex in less than 4 weeks. In fact the plants pictured are SSH, which are pretty sativa influenced.

I've had slow growing IBL indicas that took longer to show (Sensi Hashplant) and one notable sativa dominant cross (Red Congolese) that took more than a month for most to sex. So there are some strain to strain differences, but from my experience I'm not so sure the spit is along indica and sativa lines.

Here few more shots of sativa dominant plants taken on the day they showed their sex. Both plants are Island Sweet Skunk and both showed sex between 3 and 4 weeks.


Pine

 

[vonforne]

I had an ISS that was like that. Real quick. I could put her under 18\6 and she had flowers fast. Nice plant too.

And my hands get like that also.....in winter and from the work I do.

V

 

[pinecone]

Great thread Pine! It always annoys me when people say, "oh just throw it into flower for like a week or 2 and it will show it's sex" Cannabis doesn't show it's sex until sexual maturity, usually about 4weeks after sprouting. So if you sprout seeds, and then 2 weeks later throw them into flowering, and have to wait 2 weeks for the flowers to show, you're still at the 4 week sexual maturity mark.

The bad thing about putting them into flower is that they are going to take nearly just as long to show their sex whilst stretching a bunch more than they otherwise would of under veg lighting.

Also, if your seedlings aren't at sexual maturity and you throw them into flowering (under HPS with more red spectrum) you stand a chance of getting more males, since light spectrum is one of the variables when trying to get more females than males. Or am I mixed up on the light spectrum thing?

I'm not sure on the spectrum thing as I always veg under cool T5 HO's, MH, or CMH lighting. I actually hate the unnatural HPS color of HPS lighting and have a hard time accepting the conventional wisdom that it is even better for flowering than MH or CMH lighting, but that is a different topic.

Pine

 

[Rednick]

"I like this young man,
Because when he came out,
He came out with the phrase,
He went from Ashy to Classy"
http://www.youtube.com/watch?v=bDac85FabTk

Going to be trying to implement this in the future, but I still gotta do it cave man style for now, while I test my eye.

 

[luvtogrow]

Great post Pinecone! I've probably posted about early preflower sexing in veg for years but still seems people don't get the magnifier ( i use 7X eyelupe), and sex early. 12/12 to sex is silly, obviously. My experience is all strains show before, by, or right at 4 weeks from seed popping above ground. 90% by or around week 3. Earliest male for me was 12 days. It is strain dependent, and grow a sick plant and i'm not sure about sexing it. fourth node is the lowest i've seen a preflower and ninth the highest, often only one preflower at the four possible locations per node. Early sexing makes fem seeds less an option, and might be why this subject of early sexing isn't more recognized and public. I've posted about early sexing and had people jump on the thread and tell me no way. Oh yes way! You can after experience tell sex by the initial bump that starts as the preflower. The male preflower will start to be a bit more tattered on top the female more smooth, when you see seperation from the stem to the preflower, it's male, no seperation early on for the female as it appears to be more symmetrical emerging from the stem. So male kind of a stem and a ball or crabclaw, female no stem, smooth and pointy on top, pear shape or kinda like the rubber pick on the back of some toothbrushes. Female preflowers will have little stems later as they get bigger.