New Leaves curled up and twisted

I'm 4 weeks into veg and just about to put my plants into flowering.

Many of the new leaves are coming out very twisted and curled upwards. I'm holding off on flowering until I can diagnose this problem. The problems does not seem to be affecting the plants which I replanted in new soil as much as the ones in older dirt.

I've looked all around for an answer but can't find a problem for leaves curling up and twisted. They are not droopy at all.

-I only water when dried out. Once every 3 days
-I've been phing my water to 6.5 before watering
-i'm only using nutes once a week. Botanicare growth.
-temps are low. Right around 73 degrees
-no color changes or dying leaves
-it's only affecting new growth. The older fan leaves look fine.

Any ideas? I'm thinking a nute deficiency, but which one?

I'll post pictures soon.

Thanks

Here are some pics, if anyone has any ideas. I can't imagine it's too much nutes, since I only use about 40% strength once a week.

I'm going to flush some of them out to see if that fixes the problem. It can't hurt.

Philo2 said:

Here are some pics, if anyone has any ideas. I can't imagine it's too much nutes, since I only use about 40% strength once a week.

I'm going to flush some of them out to see if that fixes the problem. It can't hurt.

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I know you said that the temp is about 73 but looks like heat stress to me, How close are your lights? Sorry if I cant be more help, but I had the same problem with my first grow and the temps where at 76 and only the top fan leaves currled up like that, I backed my light off a couple of inches and the problem fixed it self.

No visible change in the plants I flushed. Overall the plants seem to be getting worse. Some leaves are rolling up like a cigarette. Picture #4 best shows the problem.

Any ideas? I'm freaking out here . I've read as much as I can but can't identify this problem. There is no discoloration to any leaves, new or old.

Checked PH of the runoff and it's right around 7.

That IS a heat related issue. There is no doubt. Too close to the lights. You have to take temp readings in different places. It's not 73 at the top of your canopy I gaurantee it! i have 2 thermometers in my tent. The one at dirt level reads 72. The one at canopy level (where the top of the plant is) reads 85. If I put it a mere 6 inches closer to the light it reads 95. BIG difference in where you take your temp readings. Also it's possible that you dont water enough. But high temp is more likely. Those leaves are curled up because they are dry and trying to retain moisture.

itsgrowinglikeaweed said:

That IS a heat related issue. There is no doubt. Too close to the lights. You have to take temp readings in different places. It's not 73 at the top of your canopy I gaurantee it! i have 2 thermometers in my tent. The one at dirt level reads 72. The one at canopy level (where the top of the plant is) reads 85. If I put it a mere 6 inches closer to the light it reads 95. BIG difference in where you take your temp readings. Also it's possible that you dont water enough. But high temp is more likely. Those leaves are curled up because they are dry and trying to retain moisture.

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Thanks for you input. I agree it looks like a heat issue but I'm just not sure.

A few things indicate it's not. I've been checking the temps everywhere and nothing comes up high. I have two ocillating fans and a large can fan. It seems to be affecting the shortest plants, the ones farthest from the light, the most. The plants that were transplanted to 5 gallon pots were closest to the light but showed the least signs of problems. The problem is also affecting the lower growth as much as the top growth. It is affecting all new growth. I had been running the lights 24 hours. I just switched them to a 18/6 cycle to see if that will solve the problem.

I let the top couple of inches of soil dry out before I water but they never drooped like they were thirsty. The problem seemed to get worse yesterday after a nute free watering. Also last night I pulled the lights all the way to the ceiling with no change.

Thanks for you help everyone. I'll keep you updated, when I come up with a cure.

What is the humidity in the grow room? It's a dryness issue. Either caused by heat, windburn (not likely), or very low RH. I'm not guessing, I've seen it before first hand.
If its not that, its got to be something really off the wall weird.
If its not hot in your growspace whats with needing 2 oscillating fans and a can fan (dont know what a can fan is). Maybe it is too windy??

itsgrowinglikeaweed said:

What is the humidity in the grow room? It's a dryness issue. Either caused by heat, windburn (not likely), or very low RH. I'm not guessing, I've seen it before first hand.
If its not that, its got to be something really off the wall weird.
If its not hot in your growspace whats with needing 2 oscillating fans and a can fan (dont know what a can fan is). Maybe it is too windy??

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Can Fan is the brand name for the inline fan attached to my carbon filter.

It can certainly be humidity related. I live in the city with the lowest humidity in the country. My gauge is telling me humidity is at 35% but that is high for indoors here. The rest of the house registers around 15%.

Thanks again. I might have to throw a humidifier in the room.

i would move the lights up after you flushed and see if that helps

Yeah there you go man. 15% would definitely do that! You want at LEAST 35%. The closer to 50 the better. The badly curled leaves will not really recover but the new growth should be much improved if you get the RH up. Good luck.

I put in a humidifier and it seems to be helping a lot. Even with the humidifier I'm only getting up to 45% RH.

I will lose some leaves but it didn't have any affect on the old growth and there seems to be plenty of new leaves sprouting.

I know we face low humidity in this area but I've never had such an extreme problem before. It's my first time with these strains and they must very sucseptable to humidity problems.

45% is good. Real good. That'll be perfect for flowering when a little dry is better to reduce any chances of mold. Way to grow.

yeah deff could have a few diff factors working together my plants where stating the sam prob my lights where also on 24/7 humidity levels are dropping cause winter is coming so i dropped my light down to 18/6 and it cured my prob good luck

try spraying your plants every day the leaves will take in water it worked 4 me with the same problem i had low humiditiy

I am having the same problem with outdoor. I was wondering if it could be a boron issue? We didn't have this problem last year and it has been more humid with cooler temps than last year. I do still live in a desert, though. I haven't found a solution yet.

I know I'm pretty late on this topic, but I honestly think this looks like broad mite damage, not heat. They are tinier than spider mites and cause that heat-stress like taco in of the leaves, esp new growth. I hope its not broad mites for your sake, I hear they're a bitch.

superskunkpussy said:

try spraying your plants every day the leaves will take in water it worked 4 me with the same problem i had low humiditiy

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If you spray, protect plants from strong light. Water droplets act as magnifying lenses, causing burn. Also be careful of bud rot if in flower.

You can hang a wet towel in your grow area to raise humidity. When my humidity is 25% the towel lasts for a couple hours. You can leave one end of the towel in a bowl of water to wick up more water as it dries. Not optimal, but better than nothing (if someone's not willing to buy a humidifier). I get by this way and my RH gets down to 20% at times.

Weedzilla710, Would broad mites live on livestock? We have horses super close to the plants.

CountessFiend, no, they are plant pests only, not on livestock. You would need to make sure you properly ID them as broad mites first though, as they require harsher treatments than spider mites and such. Here's a pic of a few of them next to their eggs, this is magnified by ~100x