Leaves are "folding" suddenly

[Heinbloed]

hello,
since yesterady ive discovered a symptom ive never seen before, ive had this starin for a long time and never saw the leaves folding in inwards like this. I havent changed any of the growing conditions and the earth is not wet nor is it time to water again...
Some are folding inwards more severe than others....

 

[SmokingWings]

When the leaves look like that some growers call it tacoing since the leaves look like taco shells. Or they call it canoeing because they look like small canoes.

Since it seems to have happened suddenly ask yourself if you changed something in the past week or so. Did you switch from bottled water to the water from the sink tap? This could have changed the pH of the water which some say is a common cause for this change in the leaves.

Another cause some growers notice is a change in the distance the lights are from the plant or even a new light.

There are a couple of other things that can cause this and I am sure that some more suggestions will be coming soon.

 

[013]

Too much light and heat, now that they’ve grown taller the fixture is too close, leaves are folding to reduce the amount of surface area exposed to the light. I’d keep a hygrometer mounted above canopy to monitor temps up there…. should run 80 to 84 F but not much more

 

[Heinbloed]

like i said above, the conditions have not changed to my knowledge. Theyre not closer to the light as usuaö, nor is it warmer. ive got about 500-550 umol on the higher leaves. With an 18/6 cycle. In mid/late summer, thats when it gets a little bit warm, but even then ive never seen this.

ive changed the pots from 10l to 15 l. But keeping pretty much the same wet/dry cycle. Instead of watering every 3-4 days, im watering evey 5-6 days now. Because they get more water on watering day.

another thing, it seems to be mostly the upper leaves that fold, not the lower ones.

 

[013]

Typically an upcan transplant makes the plants sit higher in the saddle than before which makes them closer to the light and exposed to higher temps. Only the upper leaves are affected is your clue- right?

 

[Heinbloed]

yes only upper leves, but again--its maximung 500-550 umol on the one closest to the light. they can take much more than that, even in veg. Ive had many grows in that tent with this light and its not what they do usually. Theres practically no heat in there. Maybe 25c and that only very close to the light.

 

[Keffka]

Is this a clone or from seed? How have you propagated the strain? Meaning, have you been taking cuttings from a mother or just using seeds you have?

 

[013]

maybe you are familiar with the strain but this particular pheno is reporting a problem with conditions…

A package of 10 beans doesn’t equate to 10 identical plants

 

[Keffka]

Also, what’s your humidity like? @013 and @SmokingWings are both correct that these symptoms are typically from too much heat/light. The plant doesn’t hide its working leaf surface unless it has a reason to.

While it may not directly be your light or heat, something is forcing this plant to minimize the amount of light it receives. Could be a run down mother plant or an unstable environment or even too wet of a medium. These things will make a plant weaker and less able to tolerate higher levels of photosynthesis which is what is occurring.

 

[Heinbloed]

they are clones...using the same mother plant for 1 or 2 years now...i will soon take new clones from this plant again.

humidity is like it alway is...the same i have in my room, 50-60% usually. Theres a high air exchange in that tent and there fore its not more humidity than outside. Ive never really cared about humidity and never had to. Only in the first weeks of cloning stage obviously when they are under glass.

ive dimmed the light a little bit and will wait 1 or 2 additional days before watering to get the pot really dried out. Im probably worrying too much and the symptom will soon vanish.

 

[013]

Was betting it was from seed… ahh my bad and I’m big enough to admit I was wrong there….

Still even with clones that plant doesn’t like it’s current conditions… might want to recalibrate your hygrometer.

When I went to grow shop to purchase a new hygrometer I laid 10 of their brand new (cheap Chinese made hunka-junk) devices on counter and put batteries in each. They were off as much as 12 degrees on temp and even bigger discrepancies on rh… here’s link to recalibrate >>> InTheShed calibrate hygrometers

Hmm air exchange within the room or are you vented to outdoors? The main issue is heat & light stress not humidity… one can have great air movement within a tent yet still move the same dead air around because it’s pulling from same room and exhausting to same room. It’s huge plant with gallons of wet soil so humidity inside tent can easily exceed outdoors… A plant is a water pump but it can’t pump when conditions are off.

Gotta roll will check in later but 420 team will continue to troubleshoot

 

[KeyFinger]

Either that just a genetical twist and it's okay either something causes it. Okay, what can cause the leaves to roll themselves? Temperature, air content, perhaps an infection of some sort. Do they look infected? Absolutely not. Do they look frozen or overheated? Nope...but perhaps frozen just a bit Idk, but in my opinion - no. The air remains, I guess...

 

[013]

Tacoing like that is a known light avoidance strategy the plant does to protect itself. The leaf symptoms are telling us… this plant cannot chew the combination of this much heat and this much light under its existing conditions. Right now your leaves are avoiding photosynthesis by hiding as much upper leaf surface as possible, they fold closed…

Raise the light and/or dim the light and improve your VPD and airflow…I’m thinking your hygrometer is out of whack & needs recalibration because hps in a tent should run pretty toasty

 

[Heinbloed]

what hps?
and what hygrometer?

aint using a hygrometer for a long time in the tent. Only in the cloning-container. ANd i dont use HPS. i reduced the light intensity and will see.

 

[013]

Apologies Heinbloed, my bad on the hps & hygrometer comments, I was working multiple faq page problems this morning and got a few details crossed from the other question. The other dude is running hps…. but said tent was only 70ish degrees so that’s why I was talking hygrometer stuff.

Anywho feeling really confident we nailed yours with heat / light stress causing the up taco leaf curl

 

[Keffka]

they are clones...using the same mother plant for 1 or 2 years now...i will soon take new clones from this plant again.

humidity is like it alway is...the same i have in my room, 50-60% usually. Theres a high air exchange in that tent and there fore its not more humidity than outside. Ive never really cared about humidity and never had to. Only in the first weeks of cloning stage obviously when they are under glass.

ive dimmed the light a little bit and will wait 1 or 2 additional days before watering to get the pot really dried out. Im probably worrying too much and the symptom will soon vanish.

Do you keep track of your measurements or anything? If you’ve never seen this before then something has changed. If you’re growing a clone then it’s the exact same plant you’ve been growing so it either HAS to be your environment or your mother is starting to fail. She’s kind of young for that though so I’m leaning more toward your environment.

How old is your light fixture? Is it possible you’ve got some burnt diodes giving you a red heavy spectrum?

The symptoms aren’t a dealbreaker, but they are a sign of stress that is manageable if you’ve got good plant genetics.

 

[Papa OG]

It's definitely heat or light stress.

 

[Keffka]

It's definitely heat or light stress.

I backed off heat stress cuz OP said it never goes over 78F. I guess if humidity was rock bottom this could be an issue but 50-60 rh should hold it off easily.

LED fixtures however are built with specific color ratios with red being most cost effective. If you lose a few of your white diodes you could get a red heavy light that would produce symptoms similar to heat stress, especially on smaller fixtures.

Im giving the grower the benefit of the doubt and assuming the grow is dialed in and this is an equipment related issue

 

[Papa OG]

I backed off heat stress cuz OP said it never goes over 78F. I guess if humidity was rock bottom this could be an issue but 50-60 rh should hold it off easily.

LED fixtures however are built with specific color ratios with red being most cost effective. If you lose a few of your white diodes you could get a red heavy light that would produce symptoms similar to heat stress, especially on smaller fixtures.

Im giving the grower the benefit of the doubt and assuming the grow is dialed in and this is an equipment related issue

Totally understand. But I have had plants show heat stress at lower temps than normal, and or not all strains handle the light the same way. Let alone, how it's been measured and with what it's been measured with. When I see the leaf beginning point, curl, or get aggressive looking it's trying to protect itself, its like a red light flashing.

If it was me. I would

A. Raise the light
B. Turn it down for a few until she. Lays normal
C. Make sure there is PROPER ventilation within the space.
D. Relax.

 

[Keffka]

Totally understand. But I have had plants show heat stress at lower temps than normal, and or not all strains handle the light the same way. Let alone, how it's been measured and with what it's been measured with. When I see the leaf beginning point, curl, or get aggressive looking it's trying to protect itself, its like a red light flashing.

If it was me. I would

A. Raise the light
B. Turn it down for a few until she. Lays normal
C. Make sure there is PROPER ventilation within the space.
D. Relax.

Right but that’s not an answer to what’s going on. It’s a band aid to fix a larger issue.

Perhaps it’s autism or adhd, but there is no such thing as relaxing in my mind while there is still an issue at hand. Even if I get baked, I will still obsess over the issue, I’ll just do it with a grin.

I’m not the kind of person who can just follow directions and be happy that I got the result I wanted. I have to know why I was given those directions, how they were figured out, how they work, and how can we improve it. Just knowing it works isn’t enough. Heck, you’ve seen the tangents I go off on when I’m talking to myself lol. It’s honestly frustrating and tiring and I wish at times I could just stfu and relax

It’s why I work alone or with other neurodivergent people. Normies typically don’t have the patience for my thousands of questions and long winded explanations, and I don’t blame them. It’s probably just as frustrating to them that I can’t just say “ok” and be quiet.