Leaf edges curling up

hey my plants look like that What am I doing wrong plants are 7wks old and 19 to 23 inches tall

Anyone got a real answer?

My mother in the dwc tub is doing the same thing. Definitely not heat stress as it's a whopping 12" away from the 4 bulb t5 veg light...

A couple of my plants are doing that slightly, but only the ones closest to the light. They also seem to be slightly more yellow than the average green. A couple of the other ones I have further from the light are green as hell and have no signs of stress. The only thing I can deduce from this is that some plants just favor less light.

Mcgician said:

A couple of my plants are doing that slightly, but only the ones closest to the light. They also seem to be slightly more yellow than the average green. A couple of the other ones I have further from the light are green as hell and have no signs of stress. The only thing I can deduce from this is that some plants just favor less light.

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More research tells me that it is, in fact, heat stress?

Can 80' ambient temps really do that?

Ns5 said:

More research tells me that it is, in fact, heat stress?

Can 80' ambient temps really do that?

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Look at what's happening. If they're doing that, then I would definitely say yes. My plants bathe in temps around 75-78 lately, and fluctuating humidity of 40-56%. In my case, I'd be hard pressed to say my issue was heat, especially since the lights are on movers. IMO, it's a combination of too much light, and too much heat. Like I said, the other plants I have just another 12" away from the light (horizontally) are much darker green. They are making slightly slower progress though. Chlorophyll is very important to the overall vitality of the plant, especially during flowering as a lot of the fan leaves will yellow and die off, so I've moved my lights up as well. At the moment they are about 18" away from the tops.

My plants are curling as well , 3 weeks old (kush/white widow) about 7 " tall, 400 watt mh about 2.5 feet from plants with osculating fan and 4 out of the 5 plant are curling bad on fan leaves ! my first grow its very frustrating.
Ebb and Flow - flood every 3 hours. Full veg , nice green leaves but curling bad

The leaves are trying to transpire water and they can not do it quickly enough. this is from salt build up, humidity to low - stay at 40 or above. most likely salt build up. flush with a quarter strength nut in the res water, 20 to 30% run off, check run off EC, make sure its not out of wack.

I am an advanced ebb and gro grower. You can check my posts in the grow forums. Anyway, my plants do that all the time because I keep my light as low as my plants let me. When I see them trying to curl at the edges like that I will raise my light a couple inches and within a day or two this will clear right on up as long as they aren't too far gone.......LOL. I advise everyone in here who grows with an ebb and gro system to check out my thread in the grow forum. PEACE TO ALL. Here is a video of my plants at 16 days vegging in an ebb and gro 12 site, I only use 6 of the 12 buckets. ENJOY!

[video=youtube;U5r13gmSs_A]http://www.youtube.com/watch?v=U5r13gmSs_A[/video]

From what ive researched, leaf curl is due to over dosed nutrients. If it was a heat issue, the leaves would droop(sag) as well.

I am having this problem as well. I am growing eazyryder's under a 400 hps. They are about 8 days old. The light is about 2 feet away from tops of plants. The temp stays around 80 degrees. I also have a fan that blows in between the light and the plants, which makes the plants sway a little. I use a 4 inch fan and carbon filter that kicks on 15 mins then off for 15 then on again all day while my light is on to keep my space cool. The light is on from 6am to 12am. I believe that the curling is mainly due to low humidity levels. I think i exchange enough air that the humidity stays pretty low, plus the fan keeps the plants dry.

I think i am going to leave the fan off for a day of two to see if the leaves straighten out. Even though it probably won't make a difference because of the carbon filter/fan exchanging air.

What do you think?

Hey i posted a while back with the same problem and the general opinion was heat stress as the temps were high and the lamp was close.

Old thread but...

I just started haveing this problem on my mother plant and ITS DEFFINATELY NOT HEAT STRESS. Room temp is 79 degrees under two 40 watt florescent 4' bulbs. Humidity is 50%. I grow in soil. The mother plant is 5 months old and this is the first problem I have had with her so far. My curling is only on the top new growth. My guess is salt build up. I am going to try flushing with plain water for a couple waterings.

I dont usually comment, but i will say having the same (probs?) at roughly 3-4 weeks veg under a 250 mine is not a nutes prob as theyve only had one feed which wasnt overdosed, it must be heat/light as my temps were 30/31 but last few dasy ive had door open and its been 28/30, secondly id comment that I DONT really think it is a problem at all, Im not that worried I dont think its stopping them growing in fact they are doing great for my crappy setup. sorry im blabbering, too much smoke/beer/tiredness

love & peace brothers/sisters

p.s time to roll a nice one

I have a young purple kush in a 100% organic soil mix, with my other older vegging G.D.P., and some various hybrids, and they are all about 18"-22" below three 250W hps, and one 400W mh, and the p.k. is doing the same thing. I moved up my lights because I believed it to be a potential heat stress situation as well. All my babies, 6 in total are in 5 gal buckets in a well-ventilated 4'X4' closet and are just blowing my mind every day. 'Bout two-three weeks until I induce flowering, so f'n a!

my plants are doing this aswell and im baffled... first grow 4 cloud 9's temp is between 20 and 22 celcius always and humidity is about 60 i tried raising humidity (now at 80) but they seem to have either gotten worse or stayed the same.. hard to tell, wtf? nobody seems to have a solid answer for this anywhere online

in my situation it was the light, temperature 26-27C, one 24W cfl 6500K 2" away from the plant and it was curling few leaves(plant - 8days sativa C'99). When I put like 5 inches away next day the leaves were back to normal. As

• GanjaGod420000

mentioned above, despite that it has some little curling on the edges, it still grows very nice.

Hi old post but very still very important, IMO opnion my friend grows and i have seen this quite a bit
over the years. The reason why there isnt a solid awnswer for this problem is because
it has many different factors that create the same problem, so those of you who say, heat stress, are correct, as well as
Over watering, more N, Wind burn, K etc. You see this has many factors that cause the same problem. So your all correct
and only you know how your plants doing, cause afterall their your babies and you love them. Depending on the cause this does
Not effect the end result.
King Cobra

Someone on another site said it might be potassium deficiency. There's a lot of chemistry involved, which I am just learning about. Found an interesting old biology textbook at goodwill that talks about how vascular plants carry water up from the soil into the leaves and then transpire the moisture into the air.

Basically, all the cations are competing for uptake (Calcium, Magnesium, Sodium, Potassium) and without a good balance, problems.

My little seedlings started doing this when I gave them water soaked in compost with a few drops of H2O2. It actually makes a lot of sense since the H2O2 messes with the ionic activity in the soil. Like he said, it might be heat stress, humidity issues (not for me) or something going on with the NPK profile. My experience is that most people over-fertilize.



my 2 cents

Nothing wrong with bumping an old thread instead of starting a new one eh. I have 6 diff strains in cfl cab and ONLY one plant is showing this symptom?! My heats, humidity, air exchange, media,and teas have been the same for all strains. It's a Delicious Seeds Cotton Candy at 19 days and growing like a beast. Thought it was heat, but the leaves aren't crispy and temps are fine. Should I just not worry as growth is good?!

Heat is 72F, RMH 50%, no other plant showing these symptoms, 2 light feedings(only 19 days old)I usually see this with heat stress, but growth has not stunted at all. Rep for help!