# leaves curling under



## h2ofarmer (Dec 10, 2006)

leave are curling under 4th week of flowering, not sure why any suggestions? h2ofarmer


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## OmegaVermelho (Dec 10, 2006)

humm cant open the pic dude, but anyway double check water pH, temps, RH...bla bla bla...and specially if u&#180;re using digital equipement like meters, timers and so on u should check them... i had a prob not while ago cause my EC meter was not properly calibrated...


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## h2ofarmer (Dec 10, 2006)

new pics of curled leaves


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## OmegaVermelho (Dec 10, 2006)

ok, so can u put info about your grow???what are the plants in, whats the pH, lights u know, the whole mambo jambo...cause from here i would say that they came out of a forced veg cycle if thats the case the leafs will stay like that...i have 2 plants in a ebb n flow that were REVEGED due to timer failure (this lasted only in a 24h period), the result was exactly the same as ur plants, the leafs curled but the plants are still healthy...


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## potroast (Dec 10, 2006)

Wow, those are nasty looking! I've never seen plants look that bad. Just because we don't know the reason, we can try to fix it. It's called reading your plants, and you've let this go too long without correction.
Flush. If you're in hydro, change the res. If you're in soil, flush generously.
Maybe even spray the foliage with plain water once a day. I don't think that damaged leaves will come back, but they might. What you have to decide is if you have enough room for new growth to develop before flowering. If not, then start over.

HTH


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## h2ofarmer (Dec 10, 2006)

ok the plants are in an ebb & flow machine in my closet. i have a 400 watt hps light that stays about 1' over the plants. i have two plants they are bag seed dont know the strain one looks like an indica strain and the one with the curling leaves looks to be a sativa strain.i change my reservoir every week it is 10 gallons, i use fox farm nutes at half strength,disitlled water and keep a ph of 6.0. they are in there 4th week of flowering this problem just started saturday morning,up until now the plants looked great . thanks for the help potroast and omega h2ofarmer


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## Widow Maker (Dec 10, 2006)

Your medium is prolly over nuted. Flush with pure phed water and watch how the ppm will rise back up the next day. Depending on your findings you might want to do it a couple times.
The light seems a little close. Are you using a cool tube?


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## OmegaVermelho (Dec 11, 2006)

Ok i&#180;ve done some research and what i&#180;ve found was this:

When u force a Cannabis plant to reveg (specially for short periods of time) one of the major drawbacks is the possibility of getting leaf curling without particular signs of leaf descoloration (the other is the increase of hermie plants), this phenomenon happens because the plant produces 2 dif tipes of leaf tissue in a very short period of time causing the leafs to curl or even to wry...its also stated that Haze or Haze dominant plants have an easier recovery due to their higher growth rate while Indica or Indica dominant plants due to their more compact and stacky structure and tend to take longer to recover...also the plants imunnitary system is seriously damaged in plants that are reveg, this may lead to poor yield, poor taste and low pest and plague resistance.......it would be nice to ear what more experienced growers have to say on this issue cause like i said in a previous post i experienced the same prob when a timer didn&#180;t switch off on my 3 week old flowering plants leaving them for 24h under a 400w HPS, the plants are TODAY 7 weeks into flower and they still show the curled leafs (as soon as the lights turn on im gonna take a few pics 4 u to see)...

I dunno if this sounds acceptable or if in fact u had a problem with your photoperiods but i thought i would translate the DVD info just in case...

This comment was taken from a DVD made in Spain with the participation of Ben Dronkers and Jorge Cervantes "Supergrow para Enteranos"


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## bigballin007 (Dec 11, 2006)

That is over watering I have had my plants do the same thing when I watered to often. My leaves never did recover completly but once I watered less and let the pots sit dry for a couple of days my leaves dried around the damaged parts of the leaves and the rest of the undamaged area on the leaves were fine and I was able to get an 3/4 oz from my plant that was realy close to the way yours looks.


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## OmegaVermelho (Dec 11, 2006)

bigballin007 said:


> That is over watering I have had my plants do the same thing when I watered to often. My leaves never did recover completly but once I watered less and let the pots sit dry for a couple of days my leaves dried around the damaged parts of the leaves and the rest of the undamaged area on the leaves were fine and I was able to get an 3/4 oz from my plant that was realy close to the way yours looks.



U did notice this is a hydroponics board didnt u???


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## Widow Maker (Dec 11, 2006)

Lol. Good one Omega. Good find too. +1


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## nongreenthumb (Dec 11, 2006)

I know I am still a newb but to me it def looks like nutrient toxicity. You need to flush the grow medium with 3 times as much water as the pot your plants are in. I have had leaves that look exactly like that, that was before I bought an ec/ppm meter


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## h2ofarmer (Dec 11, 2006)

thanks for the help guys, i looked at the plants today and i noticed that the plant with the curled leaves had a branch on it that had on few male pollen balls on it, i removed them from the plant, will the grow back? and if they do if i keep taking them off the plant will it keep seeds out off my bud? i changed my water on thursday and used my nutes (fox farm line)at 1/2 strength, i had been using full strenght for the whole grow and in week 2 of flowering i noticed some burning on the top fan leaves. Vi helped by informing me to lower the nutes down to 1/4 to 1/2 strenght, thanks again for the help Vi.what should i do to fix these problems? h2ofarmer


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## OmegaVermelho (Dec 12, 2006)

dude if the plant has polen sacks just kill it (even if its a hermie)...unless u want seeds in ur bud...

btw here´s a pic of my plant with the curled leafs


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## Mahstakilla (Jul 9, 2008)

h2ofarmer said:


> thanks for the help guys, i looked at the plants today and i noticed that the plant with the curled leaves had a branch on it that had on few male pollen balls on it, i removed them from the plant, will the grow back? and if they do if i keep taking them off the plant will it keep seeds out off my bud? i changed my water on thursday and used my nutes (fox farm line)at 1/2 strength, i had been using full strenght for the whole grow and in week 2 of flowering i noticed some burning on the top fan leaves. Vi helped by informing me to lower the nutes down to 1/4 to 1/2 strenght, thanks again for the help Vi.what should i do to fix these problems? h2ofarmer


you retard. are you trying to make necklaces?


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## mmaaddmmaann (Jul 10, 2008)

hey man, I had a med size chunk of my plant do that to me on my last grow. for me the leaves never recovered, and the buds associated with the leaves were smaller. my problem was that it was too hot. The upper most part of my plant got damaged from the heat coming off the light. I adjusted my light and the rest of the plant did not succumb to the same damage.


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## LOSTCOASTLOCAL (Mar 10, 2009)

It's heat damage! The leaves curl under to protect themselves from the amount of light hitting them. It's too hot!


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## SICKFREDO1 (Nov 9, 2009)

I don't think is heat problems, i use Florescent and they are cool to the touch, and my plants are curling, i think the problem is the water, they way i fixed mine was to prepare water on 2l bottles and leave them outside for a day or two exposed to direct sun light, i read somewhere that UV light will help purify the water, another thing i do before giving that water to the plants is boiling the water then letting it cool, once its cool feed your babies. thats what fixed my problem, i hope it helps


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## highpsi (Nov 9, 2009)

It's almost certainly nitrogen toxicity. Too much nitrogen will cause leaves to have a deep green color and the tips to curl downward (aka. ram horn). Too much heat, on the other hand, will cause leaves to curl upward. The outer part of the leaf dessicates faster than the inner part causing it to curl up. 

Some people are surprised that they have nutrient burn especially when they are running a fairly low EC. However, aside from simply just having too much fertilizer in solution, two other factors can cause problems. One factor is increasing the nutrient strength too quickly. Plants can take a lot more nutrient when they are introduced to it gradually. The second factor is too much nitrogen regardless of EC. If you give a plant a 600ppm solution of 90% nitrogen, you will burn the shit out of it, whereas a balanced nute mixture at 600ppm will, in most cases, be fine.

Back off the EC a good bit, and make sure your solution is well balanced (eg. calculate the N-P-K ratios to achieve approx. 1-1-1 for veg and 1-2-2 for flowering)


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## marsbars (Apr 1, 2010)

overfert my man


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## IrishDoc (Apr 2, 2010)

I had the same problem with my last grow. The upper half of the plant looked like shit and the lower half looked great. But I had other plants on the same nutes and same rez. So basically it came down to two things salt build up on the roots. Check to see if they are a tan or light brown color and flush with clean water for 3 - 4 days. And the other we figured it to be is just bad genetics in that seed. Hope this helps.


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## Ganja Geek (Apr 9, 2010)

I have a 17 day old Bubba Kush seedling that is doing this. Only thing is it's the only plant doing it out of 18. The temps 84 in my closet so it might be heat. Any suggestions?


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## needledamage (Sep 18, 2010)

I have found that leaves can curl if you have problem with fungus gnats. the larvae feed on your roots.


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## LVsFINEST (Oct 13, 2010)

It seems I'm starting to have this issue too. Yesterday, it was only one leaf curled under but today there's a couple more curling under and it all started after I changed my reservoir water. All my plants share the same water/nutes but only one plant is exhibiting this behavior, so if it was nute related you'd think all my plants would have curling leaves right? Not to mention the one plant that is having issues is the biggest/tallest by a long shot (you'd think the biggest/tallest would be able to handle the most nutes of any). My room fluctuates between 66-80F so it's probably not temp related, although since it is the tallest plant, it does sit pretty close to the light but my hand passes the "burn" test (it doesn't feel hot). Water PH is about 6.0. Highpsi mentioned that increasing the nute strength too quickly could cause it too, and that is definitely a possibility (The res was filled with water + nutes 3 weeks ago and I did not add any additional nutes when I occasionally had to refill the res). The watering schedule is shared amongst all my plants and has been the same since day one (one min on, 5 mins off - aeroponic system) so it's probably not over/under watering. I've never heard of EC nor do I have a ppm meter so I can't give numbers on those. My ladies are on their 4th week of flowering btw.

What do you guys think about this? Will my plant still produce big buds with curled leaves?


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## shaylax (Mar 2, 2011)

> When u force a Cannabis plant to reveg (specially for short periods of time) one of the major drawbacks is the possibility of getting leaf curling without particular signs of leaf descoloration (the other is the increase of hermie plants), this phenomenon happens because the plant produces 2 dif tipes of leaf tissue in a very short period of time causing the leafs to curl or even to wry...its also stated that Haze or Haze dominant plants have an easier recovery due to their higher growth rate while Indica or Indica dominant plants due to their more compact and stacky structure and tend to take longer to recover...also the plants imunnitary system is seriously damaged in plants that are reveg, this may lead to poor yield, poor taste and low pest and plague resistance.......it would be nice to ear what more experienced growers have to say on this


i have alot of success by taking clones of my plants and then just flowering those as soon as roots develop, small yield for the clone but gives you idea of the sex.


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## baconpopcorn (Mar 2, 2011)

looks like over fert, some strains are really freakin sensitive to high EC/ppm. i'd try flushing and going with a lower nute dose


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## KOOdO (Apr 28, 2011)

omg same problem ..top of plant is dark green and curling under. and the bottom is fine.i think its a combination of too much nutes and too much ,light/heat stress..im gonna try flushing.and tying it farther from the light


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## Fred West (Sep 8, 2011)

Did the flush and light spacing help you sort this issue out as i am starting to show the same signs but not as bad yet?


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## StinkBud (Sep 12, 2011)

You have your nutes too hot. Once the leaves curl under they won't come back, watch the new growth.

Too much heat causes the leaves to curl up on the edges, like you do with your tongue.

Flush with plain water and start with about half the nutes you are currently using.


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## aeviaanah (Sep 12, 2011)

I can add to the reveg topic. I had a cindy 99 try to flower on me....she has since been revegging. I got the leaf curl as well. I know for a fact I am not over feeding...although I cant say for sure if nutrients are building up in root zone. I have two other plants in the same soil same setup that are doing fine. The differences are strain and the other is trying to reveg. Ive fed once and its been many weeks. Heat could also be a problem with this...i am around 83F.

Revegging plants seem to do much better going indoor flower to outdoor veg rather than indoor flower to indoor veg.


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## JBeast (Sep 16, 2011)

I know outdoor growers can experience a slight re-veg under strong full moon light.... And that can lead to some under-curl.... Just something I've noticed through the years....


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