leaves curling under

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

humm cant open the pic dude, but anyway double check water pH, temps, RH...bla bla bla...and specially if u´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...

new pics of curled leaves

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...

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

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

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?

Ok i´ve done some research and what i´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´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"

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.

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.

Click to expand...

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

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

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

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

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

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

Click to expand...

you retard. are you trying to make necklaces?

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.

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

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

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)

overfert my man