plants not showing sex

I placed some plants into my flowering room (12/12 light cycle) exactly 13 days ago. They were all nice healthy 4 week old plants with preflowers.

First I thought they're not showing sex due to light leaks, but upon further inspection, I am 100% sure this is definitely not the case. Maybe they aren't showing sex because I had an issue with elevated temperatures for a few days when I first put them in (that's also resolved now.)

Anyone have any ideas as to what's going on here? I have no idea why this is happening. I had signs of sex in something like 5 days with my last grow.

i thought preflowers showed sex

I am into my first grow, and have had the two plants in 12/12 cycle for about three WEEKS!


I know plants grow at different rates and it might just be down to genetics, but the other one is looking good!



I dont know what I could do to progress the damn thing.
both are bagseed and random strains.
but shouldnt I see some sort of transition by now?


anyhelp is appreciated.

give it 3 weeks after flowering to see signs of sex...

3 weeks is a long time to see sex, are you sure you dont have any light leaks?

i have a semi serious problem. I have one plant almost 2months old, that has some of its new leaves come undeveloped or they look burned. Im using a 150 watt HPS sun system lamp and it is a foot away. Also im using a 40 watt cfl warmlight. I have know idea what is happening. Need help now!!!

give it 3 weeks after flowering to see signs of sex...

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3 weeks? really?? I really hope I should see some distinctive flowering by then...has anyone heard of plants not flowering after 3 weeks? And if so, can anything help the process along?

3 weeks is along time to see sex, are you sure you dont have any light leaks?

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I'm not at 3 weeks yet, but I'll be at the 2 week mark tomorrow. I definitely don't have any light leaks. My immediate thought was "oh I must have a light leak" but upon going into the flowering room in the middle of the night and locking myself in, I am 100% sure there's no stray light creeping in.

bob+marley said:

I am into my first grow, and have had the two plants in 12/12 cycle for about three WEEKS!


I know plants grow at different rates and it might just be down to genetics, but the other one is looking good!



I dont know what I could do to progress the damn thing.
both are bagseed and random strains.
but shouldnt I see some sort of transition by now?


anyhelp is appreciated.

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hey bro my plant took 3 weeks of 12/12 before it started showing sex id say give it about 3 extra hours of darkness and thats what i did and the next day i had a couple pistils coming out of it and as of now im 35 days of 12/12 and 15 days since it showed sex and next time just when your ready to go into 12/12 give it 24-36 hours of darkness and that gives the plant a boost start and also knocks off 2-3 weeks as well

does anyone know, by the way, why some plants will take 3 weeks to show sex, while others will take under a week? is it purely genetic?

I had plants showing sex after about 5 days the last grow, and the environment they were in was far more crappy (hotter, with minimal air circulation.)

It is purely down to genetics man. There are other causes to slow it down like pruning or any sort of stress prior to flowering but be patient they will start.
Nelly also gave you good advice with giving them one day of extra darkness to really get the flowerin' hormones going, but be careful to not over do it as it can cause hermies.
Just be patient and keep your current light schedule accurate. My grapefruit also took 3 weeks to start and Im in 6 weeks now and they are fat and juicy

I don't get how minor light leaks can prevent a plant from flowering. They flower outside with the moon and other lights, don't they?

I've had two strains flowering for 24 days and one is pretty well along and the other hasn't started. It's a makeshift setup so there's light leaking from a room that we vent from.

Anyways, I'm going to try putting them on a 10/14 light/dark schedule.

I've read that some strains need MORE than 12 hours of darkness to flower. Try a 10/14 light cycle for a week or so and see if that helps. Autoflowering strains won't flower on 12/12, either, they need continuous light.

sorry to jump in guys, If I have an auto flower ad don't know it, and ice had mine in flower for 6 days, do u think I caused a horomone imbalance or anything? should I treat it like a photoperiod until nothing happens then switch back to 24/0?

oops 6 yr old lol

lstdreamer said:

oops 6 yr old lol

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ijustgrowGREEN said:

give it 3 weeks after flowering to see signs of sex...

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Lets hope that ijustgrowGREEN has better grow skills now huh lol

Nocturnal Cannabis said:

i have a semi serious problem. I have one plant almost 2months old, that has some of its new leaves come undeveloped or they look burned. Im using a 150 watt HPS sun system lamp and it is a foot away. Also im using a 40 watt cfl warmlight. I have know idea what is happening. Need help now!!!

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Almost certainly the light is too close for a young plant. Increase the distance.