Plants don't want to strech ! why ???

[mriko]

Greetings people !

I started a punch of plants first of January, 12/12 from seeds. They're 4 weeks now, still not sexed, and they don't want to stretch !
THey stay short at 15cm tall max, growing rather tiny side branches than stretching toward the light, which i'd ike them to do a bit.
I'm afraid i'm going to end up with 20cm plants and have to cull them all (if it's to get 5gr each, that's a waste of time & energy, not worth).


This is the the first time such thing happen and I don't understand why. Other grow op I did starting 12/12 from seed didn't reacted like that, most being sexed at 3weeks max (most are not yet) with about double size.
Anyone anyidea what's wrong ? Low night temps ? Got a new hps, with more blue than the other I used to use, maybe that ?

Any advise will be greatly appreciated !

Irie !

 

[mriko]

moan... nobody ?

 

[headband 707]

When you say stretch what exactly do you mean they are not getting bigger once put into the 12/12 room? That is indica she prettywell stops growing where the sativa will continue ..Not sure if this is what you mean.. peace out Headband707

 

[mriko]

Thanks headband, they were started on 12/12 from seeds, but I did it many times before and by the 3rd week or so, plants start to stretch and are all sexed. But not this time. Plants are all below 15cm, except for a male which streched a little bit.

I'm thinking about too low night temps. I had not put the heater on in the room, so night temps reached 15-16°C, from around 27°C day time.
It's on from now on, so will see in the coming days if there's some change.

Also, I'm growing in coco for this session, first time I use it. Maybe some newbie mistake I made, but can't guess what.

Irie !

 

[whodair]

low temps ?? cold medium ?? too much airflow causing low humidity ?? too wet ?? some indoor winter dilemmas...

and a fresh bulb !!

 

[gaiusmarius]

can it be the strain? not all strains have a lot of stretch in the flowering phase, most do, but some indicas will hardly stretch at all in 12/12.

 

[mriko]

indeed, humidity is around 35%, certainly not enough...

I don't think it comes from strains, this session has some Peyote Purple, MiS x Af/Uz,
Uzbek x RM Burmese and HFH HashPlant which has strong haze influence.
Only the Zoe (Tajik x Orient Express) X (Uzbek Orient Express) dad is stretching

Irie !

 

[stoney917]

idk try and raise the light up 35%hd wont halt growth. maybe they just need a min if they aint show sex yet they aint flowerin yet if ya enviroment is ok u need to just be patient i have a 87nl that stays yhe same size no matter when u flipo it if i flip a 2fter she finishes at 2ft

 

[headband 707]

Hum well now that your saying your growing in coco that makes sence lol.. I tried the coco aswell and my plants looked like they were starving and they were much smaller. I would say it's your coco.. That's just my opinion good luck bro peace out Headband707

 

[irieeyes808]

low light? I have found that when they get loads of light the stretching never starts but when low light levels they always seem to lank up and look weak.

 

[Xerhoss]

I'm thinking about too low night temps. I had not put the heater on in the room, so night temps reached 15-16°C, from around 27°C day time. It's on from now on, so will see in the coming days if there's some change.

This CAN be a temp or nute issue. The night time temps are a little low. What pH or EC are you working with?
My humidity is only 27% and i'm getting up to an inch a day in early veg on my sativa doms...maybe 1/4-1/2 that with the indie girls. This at 75F 18hr light on and 65F 6hr light off on a 1000 watt MH.

 

[mriko]

idk try and raise the light up 35%hd wont halt growth. maybe they just need a min if they aint show sex yet they aint flowerin yet if ya enviroment is ok u need to just be patient i have a 87nl that stays yhe same size no matter when u flipo it if i flip a 2fter she finishes at 2ft

Lights are about 50cm above the plants, quite enough I think. the Two peyote Purple showed sex the first, at 16 & 18 days respectively. 5 other plants have sexed this week, and they're all males. I hope all others are females, 5 dudes out of 11 plants is too much...

Hum well now that your saying your growing in coco that makes sence lol.. I tried the coco aswell and my plants looked like they were starving and they were much smaller. I would say it's your coco.. That's just my opinion good luck bro peace out Headband707

Yep, been thinking about that this morning while checking the plants. I discovered to HP with lowest leves of yellowish green color. This is my first coco grow, so I certainly have to adjust myself to this new medium.

low light? I have found that when they get loads of light the stretching never starts but when low light levels they always seem to lank up and look weak.

They don't look weak, and look pretty fine actually. For my last grow, lights were lower than they are now, and plants did stretch the right way.

This CAN be a temp or nute issue. The night time temps are a little low. What pH or EC are you working with?
My humidity is only 27% and i'm getting up to an inch a day in early veg on my sativa doms...maybe 1/4-1/2 that with the indie girls. This at 75F 18hr light on and 65F 6hr light off on a 1000 watt MH.

eeeeeeheeheh, I'm a smaller player than you Xerhoss, only 150whps + 72w cfl tubes.
PH is at 5.8 and last feeding EC was at 2.4, the one before was about 1.6 or something. Only difference between the two feeding was that the 2.4 one had a full dose of growth nutes (4ml per liter).

Irie !

 

[PoopyTeaBags]

Thanks headband, they were started on 12/12 from seeds, but I did it many times before and by the 3rd week or so, plants start to stretch and are all sexed. But not this time. Plants are all below 15cm, except for a male which streched a little bit.

I'm thinking about too low night temps. I had not put the heater on in the room, so night temps reached 15-16°C, from around 27°C day time.
It's on from now on, so will see in the coming days if there's some change.

Also, I'm growing in coco for this session, first time I use it. Maybe some newbie mistake I made, but can't guess what.

Irie !

if the plants look healthy then its prob not a problem... some indica's stay very short and barely stretch at all if not at all.. 12/12 from seed with this kind of seed will not be very useful.... hybrids or sativas are best for this kind of shit...

 

[mrbiggs]

Hi mriko, Thats an awfully high EC (2.4) especially with a 222watt light.
Even 1.6 EC seems high at that wattage.
Check your runoff PH,if its dropped considerably then you got a lockout.
Good luck

 

[headband 707]

This CAN be a temp or nute issue. The night time temps are a little low. What pH or EC are you working with?
My humidity is only 27% and i'm getting up to an inch a day in early veg on my sativa doms...maybe 1/4-1/2 that with the indie girls. This at 75F 18hr light on and 65F 6hr light off on a 1000 watt MH.

You know can give a pretty low temp to plants the problem comes when the temps have a big fluctuation for example from 60 to 80 this spike is too much in one day and will cause undue stress peace out Headband707

 

[mriko]

Hi mriko, Thats an awfully high EC (2.4) especially with a 222watt light.
Even 1.6 EC seems high at that wattage.
Check your runoff PH,if its dropped considerably then you got a lockout.
Good luck

muh ? what does EC have to do with wattage ? Never heard about that, can you explain please ?
Last feeding was at 1.8, will give plain water next one, and check runoff PH.

Depsite yesterday's feeding, leaves are still yellowing and plants seems to have stopped growing actually. Moan... should have stuck to soil...



Irie !

 

[gaiusmarius]

i am always telling people coco does better in most cases when you use less then full strength nutrients. on the one hand coco specific nutrients are a great help, but mostly no set ups do well at higher then 1.4 to 1.7 in full flowering mode, in the 2 weeks after switching to 12/12 the plants can get taken from 1.2 to 1.7 or even 1.8 that seems to be the time they really need enough nutes, but only once the stretching takes off and they are visibly sucking up the nutes. till they get to that stage you have to coax them with very regular feeding at low ec levels.

good flush with phed water and then a feed at nice low ec should get them going again.

 

[mriko]

Indeed, I'm gonna lower the nutes doses.

What should be the ideal PH for flushing ? I was thinking about rising it from 5.8 to 6 (for feeding as well). Coco manufacturer (U-Grow, spanish brand, buffered and with trichodermas) announces a PH at 6.2, maybe feeding solution PH should be closer to that one of the substrat ? hmmm, sounds obvious...

Irie !

 

[gaiusmarius]

i feed the plants at ph 5.7 to 5.9 in the first 5 weeks of 12/12 then from 5.9 to 6.1 till the end, always flush at the same ph i use for feeding, but will just leave it if it's 6.2 or 5.6 but not lower or higher for flushing ideally in the middle at 5.9

 

[mriko]

Diddly...oodly... BLAH !

Diddly...oodly... BLAH !

Oh boy, I'm so upset, been checking the plants this morning and it's nothing but more males ! Damn it ! I very rarely get more than 2 or 3 males per session. Only 2 HFH HP left to sex, one I'm 90% sure will be male, the other one MIGHT be female, and a tiny sweet tooth. So that's maximum 4 females for 11 plants !
At least I've tried coco... now I'm going back to soil ! Thanks for spending the time to answer my questions everyone !

Irie !