Help!!! Plants with black crispy leaves.

First let me say ive been watching the forums and gathering information for a while now but this is my first post. IVe been reading for weeks trying to figure out the problem, but nothing quite seemed to fit the description, I have several plants that have been showing signs some pretty severe symptoms of some sort of stress. IVe been trying to put my finger on it for weeks. I would also like to say that i this grow was originally someone elses and in pretty rough shape with spider mites and a few other problems, then i took over a little over a month ago.

There are alot of variables so it makes diagnosing the problem tricky. first and foremost, its a soil grow. Primarily down to earth pro mix but a few plants are in happy frog.

temps stay between 65 and 72 generally.

There are definitely some fungus gnats still, but the spider mites appear to be under control.

it seemed like it was pretty over watered when i took over, so ive been trying to let them get bone dry before i water, but it could potentially still be a sign of moisture stress.

The plants are still in veg, about ready to be flipped to 12/12. i have primarily only been feeding with alaska 5-1-1 and roots trinity but i was given a free sample of the nectar of the gods line and used that for a few feedings. Then my PH meter went hay wire.

I continued to use the liquid bone from the nectar of the gods along with the alaska 5-1-1 for a couple feedings without having a PH meter so it could potentially be a PH problem since the problems started after the ph meter went down.

I had the first plant start getting crunchy with black curly leaves a couple weeks ago. Still had spider mites.

had been spraying with all seasons, wasnt working well enough. Did a spray with 1 0z organicide, a half oz of neem and a half oz of dr. bronners castile soap.

the next day there were two plants that showed the black crispy curly leaves.

a few days later two more plants are crispy. and when it happens it happens overnight and about 75% of the leaves turn black and crispy and must be removed.

i thought it could have been some wind burn from a fan drying out the leaves so i moved the fan. then another plant showed the symptoms.


So i guess my three main suspicions are 1) a ph problem with the soil 2) neem burn 3) moisture stress

any possible suggestions so i can stop this from happening to more plants, and potentially save the affected ones?

i know it sounds like a hot mess, and it definitely is, but im trying to save it to help a friend out. Any help would be so much beyond appreciated.

Here are some pictures. I apologize I I missed something basic but I'm pulling my hair out over this.

Too cold for veg. Crank it up 10 degrees.
The leaves look like an over feeding. Droopy. If the stalk and stems are weak then that's def it.
Veg stage you want a warmer room. 75°+ helps keep the soil warm enough to help evaporate the water from the nutrient solution, leaving behind nutes for the roots.
**It's worth noting that water needs to evaporate to break the h2o bond, that's how the roots get oxygen.
. 65° is perfect for flower stage because it replicates autumn weather.
By the pix, I think your plants aren't ready for flower.
They should be in optimal health before switching because the stress from the light change [positive stress] is what triggers the flowering hormones . You have a chance of killing them, likely have a poor harvest, if you switch while under this kinda stress [negative stress].

Looks like you did some math wrong somewhere and either added too much product into a foliar application or too much into the grow medium. To be honest they look terrible. Id say flip to flower now and get that grow behind you as fast as possible. Then start fresh. Clean the room, use the same grow medium in all plants, get some real synthetic fertilizer and a ppm meter, and really grow. What your doing right now is chasing your tail, tjeres no way to pinpoint whats causing this because it sounds like everything is wrong with these plants and you have no idea whats going on. Get real food for them and flower.

I agree with @Alienwidow about cutting your losses. Go 12/12, get it over with, take what you learned to your next grow.

I don't think your nutrients deserve as much attention *if you know what you're doing with them*. If you understand the NPK ratio you're creating with those nutrients, it should be ok. I like to do what you're doing with various bottles (see sig). But, there is a method to my madness (see sig). If you don't have a method, then a box of MiracleGro Tomato (a 1-1-1 NPK ratio) would be a safe choice. Inexpensive, balanced, simple.

az2000 said:

I agree with @Alienwidow about cutting your losses. Go 12/12, get it over with, take what you learned to your next grow.

I don't think your nutrients deserve as much attention *if you know what you're doing with them*. If you understand the NPK ratio you're creating with those nutrients, it should be ok. I like to do what you're doing with various bottles (see sig). But, there is a method to my madness (see sig). If you don't have a method, then a box of MiracleGro Tomato (a 1-1-1 NPK ratio) would be a safe choice. Inexpensive, balanced, simple.

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The tough part is seeing that theyre in two different types of soils so trying to feed has to be totally impossible. And hes using organic in soiless so thats tough as well.

I agree with he others guys. I would toss them clean your room and start again. If the strain is something you want, take some cuttings, but I don't think you can save the plants at this point.

Thanks for the replies ya'll! The good news is that maybe three look kindof un-saveable (the ones in the pictures) , and then another few are showings signs of heading in the directions of the other crunchy ones. That accounts for maybe a quarter of the total room, the rest look primarily healthy.

So the ideal plan is to get everything as healthy as i can as fast as possible, switch to flower get this shit show out of the way then hit everything with bleach and start over.

i flushed one of the awful ones with 2 or 3 times as much water as the pot size. i seem to have got my ph meter working again for a minute. as i tested my tap water and it came to 6.4 which is about right and then some distilled came to 7. so i tested the ph of the run off and it was 5.8 . then my meter gave up again.

so ive been trying to figure out how to fix any of the several meters i have or locate a new one.

So my current hypothesis is that some of the plants have been processing the nutrients better than others, and other plants have just stalled and locked out alot of the nutrients due to an acidic soil ph, and so the nutrients are just building up in the soil, not getting used, adding to the acidic ph and burning the plants.

I guess its just a hypothesis until i can get my ph meter situation resolved, but does that sound possible? could an acidic soil and leftover nutrients wreak havoc like seen in the pictures?

Is flushing all of the plants that are showing signs of the crunch a good idea?

One again thanks for the all the suggestions. Extremely happy to be an official posting member of the community. Despite the circumstances.

Theres no way that ph did that to your plants. That is the farthest thing from whats happening. Its either a feeding error or a spraying error. A flush would be ok and then statt fresh, but you need to know whats going in and what your flushing out. (Ppm meter). Seriously i havent phed in five years.

You're missing the basics of horticulture. There's a thing called transpiration. It's basically the process of water moving from root to extremity.

Are you implying that the neem oil may have clogged the stomata and is interfering with transpiration?

Missing the basics of horticulture. You need heat/humidity to aid transpiration. This movement of water from roots to tips and stomata opening and closing is what makes vegetative growth. Your leaves look like nitrogen burn. There's either not enough pores or the pores aren't opening for the nutrient/water to evaporate and photosynthesis to occur.

Put a clear plastic bag over one of them and see after a few days. The lights should warm it up in that one and you can see a difference from another.

Putting a weak plant into flower is like making a fat guy sit on a toddler chair.

p.s. He breaks the chair.

ol'dirtymastiff said:

Are you implying that the neem oil may have clogged the stomata and is interfering with transpiration?

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Quite possibly. You should really be spraying, if at all, during the first hour or so of lights out and lights on. The transitions from light to dark makes the pores open the widest to finish "work" for the cycle. Then stabilize to a normal function while it is "sleep" or "awake". Most growers only have on/off functions so this transition period is shorter. So the best time to spray is at this time when they're the widest, and you spray under the leaf. Let the top transpire.

So heres an update. i was really thinking alot about the transpiration thing and was pretty sure that was correct and decided to wash my plants off with a mild mix of castile soap and water with a good rinse after. i havent fed them anything other than water. and i started thinking about my soil ph or nutrient toxicity after someone mentioned above that it is unlikely and i dont think that could be the problem because i havent been hitting them that hard with fert, and there is dolomite in my soil blend.

Some plants seemed fine for a week after the neem spray and are just starting to get weird now. started with the weaker ones i didnt care about as much and is now spreading to the plants i really care about ( blue city diesel, durban poison). I swear it started on a plant even before i sprayed the neem, and thats what drove me to spray in the first place.

So i finally had to call one and say it was dead, so i pulled it out of the pot and inspected the root zone. There was a bunch of thin light colored bugs all over the soil, mostly concentrated between the root ball and where the new dirt from being transplanted is. ive spent the last four hours trying to get them wrangled up to pose for a photo, finally got some decent macros and a video, ill post them shortly.

Ive fully accepted the reality that i may have to scrap the entire room and start fresh, and i knew that from the beginning. However there are already several months of bills piled up and that is the absolute worst case scenario. But luckily i do have some really solid genetics grown from seed vegging in a quarantined room, but none are over a foot tall, so itd be a huge set back.

i guess the questions i have now, are as follows:

what type of soil dwelling bug could cause damage of that magnitude? they kindof look like thrips but also not. ill need some help identifying to be sure.

is it safe to take clones to try and save the genetics i have in the room? im on the fence, because if it is a neem covered leaf transpiration issue, i dont think removing healthy parts of the plant is gonna do me any favors, but if its a pest issue that is based in the soil causing the problems i would prefer to save the strains.

here is a link to the video,
waiting on pictures to be emailed over still, have em up shortly.

Thanks everyone for all the help, i know there are obviously multiple issues and with so many variables diagnosis of what is killing my plants is difficult, if not impossible. But i truly do appreciate all of the input. Had some hard lessons this week.

It's hard to tell how big that is in the video, but it looks like it maybe a springtail. Do they jump at all?

If those bugs are the cause (sounds like they are, fuckin fucks indeed), the clones you take should be fine. Give them a spray before you cut with lukewarm water to wash off the neem oil if you're worried about it. You need to cake that shit on to affect transpiration. If you stuck to the rec dose you should be good. 5ml per 2 litres for 100% cold pressed neem oil is what I use in 30+c every day and it works well. Stuff is as thick as gearbox oil out of the bottle too, so I was worried slightly at first

I didnt think it was the neem either! i have sprayed the recommended dilution of the same neem/ organicide/ soap mix every week for 2 seasons of outdoor and had zero issues at all with burning. or pests or mold or mildew for that matter. I have some pretty real world experience working with outdoor in the triangle, but am admittedly new to the indoor game. So i toned it down to just under half recommended to test it on the indoor so i was really surpised to see them suffocate.

It kindof seems like they jump but not that often. ive considered spring tails, but they seem to look a little different, and from what ive read spring tails dont cause catastrophic damage. If you have more info on them though id love to hear it.

They dont seem to like light and can kind of be corralled by it. if you leave a soil sample with them in a jar for over an hour or so they seem to disappear. They are incredibly fast.

Ive considered root aphids, spring tails, gnat larvae and none of it seemed quite right. (im not ruling any out i just cannot definitively identify it)

A couple of people on a different site composed of organic growers from my local area seem to agree on termites...

ive done some research and there is a such thing as subterranean termites where i live, and they can feed on plants and roots.

been trying to ponder on how we could have gotten termites. We did use a few bags of soil that were stored in an old wooden shed......

Has anyone here ever even heard of such a thing?

ol'dirtymastiff said:

View attachment 3575870 View attachment 3575871 Here are some pictures. I apologize I I missed something basic but I'm pulling my hair out over this.

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Sounds and looks like light deficiency. I kinda stopped reading after "originally from somewhere else". That was my assumption before reading the thread, though I could be wrong.