Leaves sides curling up... need help!

This is my first growing experience, i’ve experienced a lot of problems, but now i got one plant that certain leaves are cupping up like a taco and i want to know how to fix that and make it until the harvest…
I have 3 plants total that are growing outside on my balcony in pot around 2-3 gallons!
I feed them with tap water, all with mostly the same amount and let the soil dry enough between each watering! I don’t give them any nutes, just what was in the soil that i bough at the garden store!

my crop:

The one with curly leaves :

As you can see it’s not all the leaves that are cupping up, mostly at the top

One is already flowering:

I had to remove a lot of dead leaves on this one and the tip and side of some remaining leaves are brown and crispy but the bud site look healty…

And the third one:

A little bit of yellowing tip on some leaves but the new leaves are looking good…

As you can see, i got some issues with all 3, and now i’m struggling with those cupping leaves and wondering if someone can help me with that !
all 3 are planted in a black pot like the one who is already flowering, i just put the others in a white container to prevent the soils to dry to fast and roots burn.

I can give more infos if needed!

I think that the “tacoing” or “cupping” leaves are caused by heat stress but not sure. What are the temperatures during the heat of the day?


Temps where around 28-30C and kind of humid in the past week but back to normal for last 2 days with 22-24C and normal humidity, i was wondering if it’s was that but they are all 3 in the same spot and only one plant have cupping leaves…


Different plants (even within the same strain) can react differently to various conditions. While 28 - 30 is not terminal for them it is a bit warm.

The actual temperature at each plant can also be different especially if there are any surfaces around for the light to reflect of off. Still looks like heat stress but other things can be involved as well, I just lack the knowledge and experience.

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Ok thanks for answering, do you think the leaves are gonna come back to normal " flat" leaves with time or not ?!

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That depends whether they are actually damaged or not. The parts of the leaves that are not damaged may recover. It looks like they are sitting in a protected area, it might help to have a fan blowing but not directly at the plants, just get them moving a little bit. This may not help but won’t hurt them.

Edit: I looked again, the sun beating down on the deck can get pretty warm (hot).
Also, too low humidity and too high temperatures are a recipe for difficulties.

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I was thinking that too yesterday and that’s why i put the white containers under my black pot to help keeping the roots cooler but maybe it’s not enough, gonna try to place them in another spot and see if they like it! Humidity is always in the 60-70 or higher, im in Quebec CanadaS, always humid here :wink:

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The white containers may help keep the roots cooler but the actual air near the hot deck surface is what I am concerned about. You will get a combination of radiant heat from the deck surface plus the air is heated up and the sun is beating down on the leaves. All of that may have too much for the one plant. One of the others appears to have had a lesser reaction to the conditions. One of them seems to have fared quite well.


Ok thanks for the advice, i’ll try to figure out what i can do to reduce this effect and keep them on the deck where its a bit more undercover… maybe some artifical grass on the deck where i put the pot to cut the reflective effect and heat :thinking:

This is almost certainly a sign of heat or light stress. Easy to fix though. All you have to do is put them in some shade during the hot part of the day. Putting them on grass will help also.
Another thing I would suggest is to feed them now! At the very beggining of stretch and flower, the plants will be consuming copious amounts of Phosphorus.
I made the same mistake and a lot of my girls went from green and lush to extremely deficient in less than 2 weeks.

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Great job mentoring!

I was only going to add that it looks like heat stress: water twice a day when you see that which should help, a bit of silica will help with heat stress as would a small P, K boost (phosphorus helps with heat management). You should also put in shade when too hot although 30C (78F) is nearly perfect.

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Thank you, @Myfriendis410, and thanks for stepping in and completing the task.

Not meaning to be anal about it but 30 C is 86 F, 25 C is 77 F.

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Ok thanks guys :pray:!
I’m gonna try to put them in another spot and maybe in the shade for the middle of the day and put them back in the sun later in the afternoon…

For feeding i bought this product but for the flowering stage…

i wanted to figured out my leaves problems before giving them something…

Can i give this solution to the 3 plants or just the one that is flowering? Need to buy other nutrients for the ones that are not flowering yet ?

See? I used 20C not 30! Duh. 1.8 X degree C plus 32=78F? 30C would be 86F and a little bit hot. Especially in sunlight.

Thanks for bitch slapping me straight haha.


That ferilizer is higher in Potassium, so it might be better for late flower. If they are just starting their stretch and flower, need more Phosphorus.
Bone Meal and Rock Phosphate are both good sources of Phosphorus.

So this might help me ?!?

Do you suggest me to buy something else to stop the leaves taco’ing ?!
I read that Rhino skin from advanced nutrients might help with heat stress and others issues…

Or should i buy a kit like this one and give a little bit of nutrients, like half the recommended dose ?

You can get a 3 bottle nutrient line for, I think like $30 for the Fox Farm trio on Amazon.
You can use the pro mix bone meal too but it’ll be a more slow release of nutrients compared to bottled nutrients. But either will work.
If you want to use the Advanced Nutrients Big Bud, I would suggest getting a bottle of Advanced Nutrients Overdrive. It has more Phosphorus I believe.
I’ve heard you don’t really want to mix brands when it comes to bottled nutrients.

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A little update on my plants, everybody seems to be in good shape, the leaves have stop tacoing on the one that did it and the new leaves are more normal!
I think the other are fine, i only watered them with around 6.5 ph tap water since i realized that my soil already have for 3 month of organic fertilizer in it…
i gave a half dose of Big Bud to the one flowering and that’s all !

And i have a question, is this the first sign of flowering so i can start the count for the 1st flowering week for this plant ?!

Thanks !

@Sto_418, yep… start of flower

Ok thanks !
So i’m counting around 8 weeks from now to be ready for harvest, it’s gonna be close to november by then, and colder temperature here up north in quebec, canada. Do you think they gonna flower even in temperature around 18C in the day and 6-7C in the night… ?!

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