Leaves Tacoing Under Optimal Environmental Conditions (Causes & Fixes)

[zyzyx]

Hi all, I’ve read a ton and actually pm’ed a handful of experienced growers and we’re still in the dark with this issue so I thought I’d make it public and hope we can get to the bottom of this. So… to state the obvious, SOMETHING isn’t optimal… but what?

I have an indoor garden (10x20ft grow tent) with 36 plants inside. 10 different strains. I have x6 Gavita 1700e LED lights positioned 26 inches above my canopy and the fixtures are currently on 70% power as we’re on week 7 of veg. Most plants are exceptionally happy and health with the exception of 2 Orange Sherberts.

These plants are shorter than most in the garden, and they are positioned closest to a 16" oscillating fan.
All other plants including 2 more Orange Sherbert’s are looking fine.

Haven’t checked runoff PH yet but will do later today. I’m thinking it must be diet as light/heat are in good ranges. (Temp is 82 but with LED lights so less radiation). RH is 62 in tent.

Taco is only on new growth.
Any ideas?

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[Moderator note]

Quick answer: “tacoing” leaves (edges curling upward) are usually linked to environmental factors like light intensity, heat, humidity, or airflow—even when conditions seem optimal overall.

Small imbalances can still cause this response. For example, light being slightly too close, airflow hitting the plant directly, or humidity being a bit too low can all lead to leaves curling upward.

If tacoing is mostly happening on the top leaves closest to the light, it’s usually related to light intensity or heat at canopy level. Raising the light slightly or increasing humidity is often enough to resolve it within a few days.

Common things to check:

• Light distance and intensity
• Temperature at canopy level
• Humidity (VPD)
• Airflow direction and strength

Even in otherwise dialed-in environments, adjusting one of these slightly is often enough to resolve the issue.

[kettle]

im sure I’ve seen this room with issues before…it was humidity right?

[garrigan62]

@zyzyx

Look into this ok?

It has been my experience that the “tacoing” is a sign of only a couple things. Heat and/or humidity issues can cause this to happen. Typically, if it is heat ffrom the lighting then the leaves showing the signs will be at the top of the plant. If humidity is an issue then it will show on the leaves that get hit by the fan or moving air the most. This happens sometimes when the air inlet is blowing dry or humid air onto one or two plants. It will show on one side of these plants but not the other, or if there is a ffan blowing down warm, dry air from above onto one plant.

However, the other thing that is fairly common for causing a little “tacoing” that shows on lower to middle leaves is going to be an early sign of magnesium deficiency. Sometimes the mag deficiency will also show a little bit of faint yellowing on the affected leaves in between the veins of the leaf fronds, or even a very faint lighter green outline of each leaf frond as if someone took a lime green highlighter and went around the edges off each frond on the affected leaves

[BobbyDigital]

Have you looked into pests? I’ve seen where broad mites can cause damage that looks a lot like that.

[zyzyx]

I haven’t checked for pears yet… man that’d be unfortunate… it’s so cold out right now that they would have had to get transplanted with incoming soil or something.

Heat and humidity seem to be stable now but these two were def. the closest to a fan so now that they’ve been moved I’ll see if the newest growth looks better later this week.

We also flushed the plants with water twice yesterday to break up any salt or Nute buildup near the roots.

[Myfriendis410]

FYI ambient temperature is not necessarily canopy temp. I would reduce the light intensity: maybe drop down to 50% and perhaps even consider a shorter day cycle for everyone.

@garrigan62 tuned you up.

[Cannabian]

They do look pretty dark green! ?

[elheffe702]

@zyzyx

they are positioned closest to a 16" oscillating fan.

I think this is the culprit. Are they getting more wind than the others? They need a breeze, but not too much. I don’t think it’s pests, or your entire grow would have the same issues.

[peachfuzz]

I believe @elheffe702 is on the right track…
They look wind blown to me …
Move them to a different place and see if that helps…
Oh ya , dangit … I’ll get you a pic of that watering schematic…

[Cannabian]

Yeah wind can be a pain. I think smaller oscillating fans are better because they are gentle and yet move air. Clearly moving either the fan or the plant ts is a great place to start.

[zyzyx]

I’ve moved both plants away from the fan (and replaced them with two others…) so we’ll see what happens next week. Thank you for the feedback all.
I’ve also flushed both pots as my grower thinks that it’s nute burn.

[LoCoRock]

Good luck man your gonna be manicuring for weeks!! Hello bowl trimmer. LoL
The room looks awesome though

[zyzyx]

Seriously… hello college kids!!

[zyzyx]

So after flushing the plants out and moving them away from the fans one looks slightly better and one looks slightly worse. The third plant is still hanging on to the edge where something looks like it’s about to go wrong but it’s not as obvious as these two.

I’ve raised the lights and these guys are surrounded by other taller plants with no signs of the tacoing.

[Cannabian]

They look healthy green? Dont look burned? Could be a genetic abnormality? Alien Rift quite frequently has frilly edges on the sun leaves, most pronouncedly during the end game. So perhaps it’s a genetic abnormality that happens when the plant sexes? Just guessing of course?

[peachfuzz]

Lookin more like nutrient overload…
Now that you moved them from in front of the fan…
What’s the ppm on runoff… ?
Ph may also be an issue…
Check that as well…

[zyzyx]

So, things are looking slightly better but now I’m seeing these Nute deficiency signs on the leaves. Could this be from splashing water on them or do they need some cal/mag/manganese? I’m going to take a water runoff reading tonight and I’ll update PH and PPM but the water is dark brown and smells.

!

[Cannabian]

Hmm? Dark brown and smells? That could be anaerobic soil? Possibly over saturated? Bad drainage? Bad bacteria making that smell? Ive had organic stuff sitting in water will begin to smell putrid after a while.

[Stonedrus]

@Cannabian, I agree with anaerobic decomposing, a light h2o2 mix in the water should aerate the soil and reverse this

[zyzyx]

Okay so I’ve got pics with an update. 2 of the 3 plants are doing MUCH better. I still don’t think this is light stress as even the lower leaves (under shade from above) have the taco/twist/curl going. One other interesting effect is that these buckets take significantly less water than the other 33 in the garden. They start start spilling water out the drain holes at 1/2 gallon while the other 33 buckets take 1 to 1.2 gallons without much dripping. Does this mean there are more or less roots in these 3?

So to recap, we flushed with regular water after the severe tacoing, and then skipped every 3rd nutrient feeding in favor of straight water and additionally stopped using RO water in favor of tap water ph’d down to appropriate levels. This is because the tap water has some minerals in it that RO does not.