Question about going to 12/12 for sex, then back to 20/4

My plants are 21 days old since the sprout popped out of the soil, and I want to go to 12/12 for a week to get the sexes to show, and then back to 20/4 to veg some more and to cut clones.

How long after I switch back to 20/4 from 12/12 will sexes show? How long does it usually take in 20/4 or 18/6 for a plant to show preflowers without going into 12/12?

Thanks.

This is an interesting thread. I will watch it. I've often wondered if it was even possible to induce flowering stage for sexing and then going back to veggie. However using my education in biology and chemistry I would theorize that once certain hormones are released into the plant signaling it to flower it cannot be reversed. Almost like puberty. The plant sees winter coming... knows it needs to reproduce, sexes out male/female and then prepares to do it's business. I'd like to know how my theory holds up.

Some people seem to not like doing this because the stress can cause plants to hermie but others do it regularly. Hopefully someone who does it will chime in with some good info.

Take clones and sex them. Much safer. Don't stress the keepers!

AJ Toker said:

My plants are 21 days old since the sprout popped out of the soil, and I want to go to 12/12 for a week to get the sexes to show, and then back to 20/4 to veg some more and to cut clones.

How long after I switch back to 20/4 from 12/12 will sexes show? How long does it usually take in 20/4 or 18/6 for a plant to show preflowers without going into 12/12?

Thanks.

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in 3 days you will be able to tell and its not going to stress them out to cause a hermi.

mygirls said:

in 3 days you will be able to tell and its not going to stress them out to cause a hermi.

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So if I 12/12 for 3 days, then go back to 20/4, that should be enough for them to be sexed?

AJ Toker said:

So if I 12/12 for 3 days, then go back to 20/4, that should be enough for them to be sexed?

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when you switch to 12/12 how long does it take any plant or most plant to show pre flwer or their sex, mine 3 or 4 days.

Ok, great. I'll do that then. Then I can cut clones for future mothers and flower these ones. Next purchase is a 600w HPS with a cool tube! Thanks again for the clarification.

A lot of strains will show pre-flowers at around 4 weeks,
I've read about giving them total darkness for 48 hours and about 2 weeks later
they will show sex,
You can also put something over 1 branch to give it 12/12 for a couple of weeks
and then only that branch will show sex, or clone and put them under 12/12
I could go on, but I like to just start looking for pre-flowers with a 30x scope at the 4 week mark, works for me anyway.

Whenever I veg for along time. My preflowers show in about 2 months.

you can do it, ive done it, no probs
my monster plant in my garden was flowered under a light indoors to make sure it was female, then revegged indoors to get it growing, then put in the garden to keep vegging.
when i put it in the garden it was maybe 1 foot high. now its about 5 foot 6 or so and still going strong.
its the mother in my grow journal in my sig

spiked1 said:

You can also put something over 1 branch to give it 12/12 for a couple of weeks
and then only that branch will show sex.

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this is another option for you

I do it every winter for the up coming grow season.. No worries!

i was going to take 20 good seeds thc bomb. grow for few weeks and then sex and remove males. then veg again and take clones from the best females to become mother plants. what do you think? i think the stress wont matter because the clone wil grow healthy with the same genes right?

You can take a dark garbage bag, and some tape and make a sleeve, like a shirt sleeve, and put the sleeve over ONE branch for two weeks, and let that ONE branch show sex.
In my humble opinion, what you are proposing to do, switching back and forth, is not wise..

Roseman said:

You can take a dark garbage bag, and some tape and make a sleeve, like a shirt sleeve, and put the sleeve over ONE branch for two weeks, and let that ONE branch show sex.
In my humble opinion, what you are proposing to do, switching back and forth, is not wise..

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very good i remember that now. its a lot better then putting the whole plant in 12/12

Little off topic but here we go, i have two females who have been showing massive preflowering now for about a week and a half. i am 27 days in from seed. What i am wondering should i start using my (Fox Farm) tiger bloom now or wait till i go 12/12?? I am still currently feeding heavily wit Grow big and big bloom no signs of burn and i flush every 7 days.. Any fox farm veterans or any info much appreciated!!

i give mine bud blood only a week b4 flower.

hey guys im right with you with this one! Alot of people have different ideas. In my local area i know a total of three growers including myself. We all argue about this and it can get rather touchy. I myself like to wait and let preflowers, however recently i have breed a strain with a himalayn gold and a g13 power skunk. Very nice breed. Point being the first few times around i waited for almost 3 months and no preflowers or sex. I like the clone method, meaning i clone then simply sex the cloned plant while my hoped to be mother stays comfy in veg. As these other gentlemen they use the 12/12 then back to veg without ever having a problem ( we all play poker, lets just say their luck is always better!) I just called one of them and asked about the the hermie, i was told "not a one in 8 years" so i suppose different things work for different people. We are simply trying to mimic nature and the sun does not fluctuate it cycles. to show sex.

Oh i have read about and just started to use a product called open sesame. pretty sure its made by fox farms and it is to show sex and help develop preflowers. hope this helps .