Help! What is this on my leaves?

MJmadscientist · Aug 18, 2025

Hey there all you outdoor growers! I need some help with this one.
I usually have some leaf spots by the end of the season but this isn’t the norm.
I’ve been battling with a little septoria. Nothing horrible but worse than years past due to our weather this year.

I’m getting spots on one plant worse than the rest. It not really affecting the others and I’m wondering if it’s a form of nute burn or if it’s a fungus too?
It’s very symmetrical and affecting the serration area of the leaves

Flavio · Aug 18, 2025

insects

JIMKSI64 · Aug 18, 2025

Thrips & Cannabis - How to Identify & Get Rid of It Quickly!

If you see tiny, wormy little bugs, dark winged insects or bronzed discoloration on the leaves, you may have thrips. Learn how to get rid of them!

www.growweedeasy.com

MJmadscientist · Aug 18, 2025

Flavio said:
insects

That’s been taken care of. Those were those dang flea beetles.
Spinosad, neem, and copper took care of them.

Those brown spots showed up 2 days after a feeding and spraying copper fungicide

MJmadscientist · Aug 18, 2025

JIMKSI64 said:
Thrips & Cannabis - How to Identify & Get Rid of It Quickly!

If you see tiny, wormy little bugs, dark winged insects or bronzed discoloration on the leaves, you may have thrips. Learn how to get rid of them!

www.growweedeasy.com

Again I’m looking at the bronze colored spots that go down both sides of serrations.
They are very even and it’s odd to say the least

All my girls had some thripe and flea beetle issues but I’m back to good clean growth on the top canopy for a while now.

This is something new and it affects new leaves every day that passes. I would say it’s working its way up to the top. More Mature leaves get affected and internodes are not. Top colas aren’t affected yet either.

JIMKSI64 · Aug 18, 2025

Bugs can and will bring infections. May be a fungus from the bugs.
I do not grow pot outdoors but have learned after treating for bugs on food to let the plant dry out seems to reduce infections from bugs.

Ninjadogma · Aug 18, 2025

Thrip damage showing on the leaves but that brown stuff going on at the guttation points around the edges of the leaf looks like maybe a nute or pH burn.

How does your water look? I posed a related question to an AI and it suggests taking a peek at chlorine and fluoride levels. I gotta admit AI made a good point. If it's happening across all your plants, what do your plants all share in common and presumably they all get the same water.

JIMKSI64 · Aug 18, 2025

Ninjadogma said:
Thrip damage showing on the leaves but that brown stuff going on at the guttation points around the edges of the leaf looks like maybe a nute or pH burn.

And when roots die from pests the pH moves.
Kill chain.

MJmadscientist · Aug 18, 2025

Ninjadogma said:
Thrip damage showing on the leaves but that brown stuff going on at the guttation points around the edges of the leaf looks like maybe a nute or pH burn.

How does your water look? I posed a related question to an AI and it suggests taking a peek at chlorine and fluoride levels. I gotta admit AI made a good point. If it's happening across all your plants, what do your plants all share in common and presumably they all get the same water.

So it’s just really this one getting its ass handed to it.
Water is naturally neutral btw.
The rest look pretty great. I’m no chemist but I do alright with my mixes.
I think this is something to do with nute burn but with that septoria showing up in past I worry.

It’s very very symmetrical. If a leaf has it all fingers show. That browning on serrated points affected but just inside the edge of leaf.
It’s weird. They get the exact same. Half gallon of water or nutes per pot when watered.
I make 5 gallons and dump whatever is left on the garden.

Ninjadogma · Aug 18, 2025

MJmadscientist said:
So it’s just really this one getting its ass handed to it.
Water is naturally neutral btw.
The rest look pretty great. I’m no chemist but I do alright with my mixes.
I think this is something to do with nute burn but with that septoria showing up in past I worry.

It’s very very symmetrical. If a leaf has it all fingers show. That browning on serrated points affected but just inside the edge of leaf.
It’s weird. They get the exact same. Half gallon of water or nutes per pot when watered.
I make 5 gallons and dump whatever is left on the garden.

Exactly. There's like capillaries in the leaves that extend to the edges of a leaf and they will for lack of a better word, perspire sap from these spots and it's called guttation. So what we are seeing is necrotic spots where guttation occurs. That kind of tells us there's something toxic in the fluids of the plant. It wouldn't be septoria. That usually has a distinct yellow zone between the green and the brown. Since you are sure it's not the water, it's likely excess nutes, I'm guessing nitrogen burn.

Edit: Related thought, how much water are you giving that plant? Guttation is a natural thing but it also happens when there's excess water. It can't hold any more so it literally oozes out of the plant.

MJmadscientist · Aug 18, 2025

it gets 1/2 gallon for a 5 gallon fabric pot. I’m having trouble keeping up with water right now. Lots of heat evaporation. I get a couple days between watering if I’m lucky. I had a heat spell and was on it 1-2 times daily. Coco airy mix. Pots getting light as air at end of dry cycle

I may have burnt it. Just not the nute burn I’m used to seeing.

If it’s not fungus then it makes me happy. I was worried she was gonna end up on an episode of naked and afraid. she was going to the forest to be with her people with these struggles.
I didn’t want her zombi cooties spreading to the others.

Help! What is this on my leaves?

Help! What is this on my leaves?

MJmadscientist

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