Problem with seedlings, mottled brown spots on leaves

CC57 · May 3, 2026

Hope somebody can help. Started about 200 seeds in early April. Had great germination. Initially under LED lights indoors but I put over half out in my greenhouse. Plants in the greenhouse look fine.
Some of the plants under LED look like this. Soil mix is Pro Mix with Perlite, Earthworm castings and Biochar. Having problems with humidity indoors. Humidity very high especially in the early morning. Lights indoors are 20 hours on 4 hours off. Planning to move all indoor plants into the greenhouse as it appears something indoors is the problem. Planning to put all plants outdoors, planted in ground in a week or two as weather allows. But, I'd like to correct this problem. Any help appreciated. Leaf septoria or nutrient deficiency?
Hope somebody can help. Started about 200 seeds in early April. Had great germination. Initially under LED lights indoors but I put over half out in my greenhouse. Plants in the greenhouse look fine.
Some of the plants under LED look like this. Soil mix is Pro Mix with Perlite, Earthworm castings and Biochar. Having problems with humidity indoors. Humidity very high especially in the early morning. Lights indoors are 20 hours on 4 hours off. I moved all indoor plants into the greenhouse as it appears something indoors is the problem. Planning to put all plants outdoors, planted in ground in a week or two as weather allows. At this point, root systems on all look healthy. If anything, they are getting rootbound in the six inch pots. I'm chancing the weather but I'm seriously thinking of putting them all outdoors right now. But, I'd like to correct this problem. Any help appreciated.

Phyto · May 3, 2026

Looks like it might of gotten a bit too much in the way of nutes. The new growth looks decent, but the crispy green leaves is usually a nute issue.

GNick55 · May 3, 2026

CC57 said:
Hope somebody can help. Started about 200 seeds in early April. Had great germination. Initially under LED lights indoors but I put over half out in my greenhouse. Plants in the greenhouse look fine.
Some of the plants under LED look like this. Soil mix is Pro Mix with Perlite, Earthworm castings and Biochar. Having problems with humidity indoors. Humidity very high especially in the early morning. Lights indoors are 20 hours on 4 hours off. Planning to move all indoor plants into the greenhouse as it appears something indoors is the problem. Planning to put all plants outdoors, planted in ground in a week or two as weather allows. But, I'd like to correct this problem. Any help appreciated. Leaf septoria or nutrient deficiency?
Hope somebody can help. Started about 200 seeds in early April. Had great germination. Initially under LED lights indoors but I put over half out in my greenhouse. Plants in the greenhouse look fine.
Some of the plants under LED look like this. Soil mix is Pro Mix with Perlite, Earthworm castings and Biochar. Having problems with humidity indoors. Humidity very high especially in the early morning. Lights indoors are 20 hours on 4 hours off. I moved all indoor plants into the greenhouse as it appears something indoors is the problem. Planning to put all plants outdoors, planted in ground in a week or two as weather allows. At this point, root systems on all look healthy. If anything, they are getting rootbound in the six inch pots. I'm chancing the weather but I'm seriously thinking of putting them all outdoors right now. But, I'd like to correct this problem. Any help appreciated.

what pro mix you using?
how often you water?

GNick55 · May 3, 2026

GNick55 said:
what pro mix you using?
how often you water?

why lights at 20/4?
what will be your daylight hours for outdoors when they go out?
200 seeds?
how much experience you got?

GNick55 · May 3, 2026

GNick55 said:
why lights at 20/4?
what will be your daylight hours for outdoors when they go out?
200 seeds?
how much experience you got?

are those plants sitting on the cement floor? is the floor cold?

JIMKSI64 · May 3, 2026

Whatever it is it does not appear to be touching the new growth. How long was this lower presentation and do you have pics of the creep as it started?

Ninjadogma · May 3, 2026

Mag pleating and K crisping and probably related to colder roots. If cold can be eliminated as the culprit, then look at your watering practices or soil pH before looking at nutrient profile, based on that just being promix with some EWC.

Hossgrows · May 3, 2026

I'm with Ninja
Mine are in ProMix BX with dry organic nutes, but under T-12 lights.

A very light feeding after first week , then a full feeding two weeks later. Plain tap water with good pH every 2-3 days, 70°f ambient temperature.....no problems.

Mine are in 6" pots at 5&7 weeks.

Soil might have been a bit hot for sprouts at the start, but have grown enough to handle it. ProMix states having enough food for a week without amendments. I'm also a dry environment....furnace is running.

16/8 at the beginning, moving in increments to 14/10 to mimic outdoors daylight times before transplanting into my garden.

CC57 · May 4, 2026

GNick55 said:
what pro mix you using?
how often you water?

Using Pro Mix "Garden Mix" with perlite, earthworm castings and biochar. Watering once a day. Plants have been in 6" pots for two weeks now. Definitely getting rootbound although roots appear healthy.

BearWater · May 4, 2026

CC57 said:
Watering once a day.

need to re evaluate this : )

How much are you watering when you do water?

Try giving them a good soak and then letting them dry back a bit. Feel the pot, let it get light.

CC57 · May 4, 2026

JIMKSI64 said:
Whatever it is it does not appear to be touching the new growth. How long was this lower presentation and do you have pics of the creep as it started?

Limited to lower leaves. Top growth seems fine. Will probably put these outdoors in the ground on Wed May 6th. We currently have forecast for a hard freeze on Tues the 5th. Putting them out so soon would be risky as I have seen hard freezes and snow in mid to late May in the past. But these plants are tough. I've had experience with mid to upper 20s and snow in the past and they generally fare well. Here's a photo from 2024 grow, mid May planting, did not lose any plants.

CC57 · May 4, 2026

I did start with 200 seeds, 36 different strains. Many are landrace genetics. Some are crosses I've made. Generally have great results with anything from the Middle East as my conditions here are similar and they tend to flower early and fast (semi auto flower trait). My biggest challenge is with equatorial sativas. They get very large but don't flower until mid-late September due to my location at 45 degrees N latitude. So light dep is the only way to grow equatorial sativas outdoors where I am. My experience? Grew some Columbian Gold and Thai Stick seeds in 1974, under flourescent grow lights. Took forever for those plants to flower and mature but the buds I got were pure fire. That was in my bedroom closet, parents had no clue. Did a guerilla grow in NJ in the mid 90s. Started some bagseed. Then took one of the females, planted into a five gallon bucket full of soil nestled into a talus slope on a mountain with excellent southern exposure. That plant yield about four ounces of choice bud. In July 2o21 I was diagnosed with PCNSL brain cancer, did four rounds of chemo and ASCT, finishing treatment in Jan, 2022. Chemo side effects were horrible and cannabis was a godsend. So I decided to grow my own herb. Started indoors under LED but quickly discovered that growing outdoors in ground gave much better yield, taste and potency compared to indoors. Indoor grow for me was a PITA, trying to control humidity, temperature, etc although I have grown some nice bud indoors. Outdoors, I leave it all up to Mother Nature, native soil and abundant sunlight. My only challenge outdoors is dealing with grasshoppers but the plants grow faster than the grasshoppers can eat. Some photos of outdoor grow:

TerpBeans · May 4, 2026

Looks like you know what you're doing bro

Im glad you're back on your feet after your battle

GNick55 · May 4, 2026

CC57 said:
I did start with 200 seeds, 36 different strains. Many are landrace genetics. Some are crosses I've made. Generally have great results with anything from the Middle East as my conditions here are similar and they tend to flower early and fast (semi auto flower trait). My biggest challenge is with equatorial sativas. They get very large but don't flower until mid-late September due to my location at 45 degrees N latitude. So light dep is the only way to grow equatorial sativas outdoors where I am. My experience? Grew some Columbian Gold and Thai Stick seeds in 1974, under flourescent grow lights. Took forever for those plants to flower and mature but the buds I got were pure fire. That was in my bedroom closet, parents had no clue. Did a guerilla grow in NJ in the mid 90s. Started some bagseed. Then took one of the females, planted into a five gallon bucket full of soil nestled into a talus slope on a mountain with excellent southern exposure. That plant yield about four ounces of choice bud. In July 2o21 I was diagnosed with PCNSL brain cancer, did four rounds of chemo and ASCT, finishing treatment in Jan, 2022. Chemo side effects were horrible and cannabis was a godsend. So I decided to grow my own herb. Started indoors under LED but quickly discovered that growing outdoors in ground gave much better yield, taste and potency compared to indoors. Indoor grow for me was a PITA, trying to control humidity, temperature, etc although I have grown some nice bud indoors. Outdoors, I leave it all up to Mother Nature, native soil and abundant sunlight. My only challenge outdoors is dealing with grasshoppers but the plants grow faster than the grasshoppers can eat. Some photos of outdoor grow:

ya sounds like you know what your going,
the thing with the indoor plants is your watering everyday because as you do that, every watering will release more of the amended nutrients in the pro mix causing lockouts,,

CC57 · May 14, 2026

At this point, most plants are in the ground growing outdoors. A dozen are in the greenhouse and will be used primarily for breeding. The burnt crispy leaves have mostly been a non issue. All root systems were healthy. Plants outdoors are thriving and putting on new and vigorous growth. My soil outdoors is fine sandy loam. Back in October, I added composted sheep manure, perlite, biochar and wool pellets. So compared to prior years, the soil should be much improved now.

dumber · Jun 11, 2026

CC57 said:
At this point, most plants are in the ground growing outdoors. A dozen are in the greenhouse and will be used primarily for breeding. The burnt crispy leaves have mostly been a non issue. All root systems were healthy. Plants outdoors are thriving and putting on new and vigorous growth. My soil outdoors is fine sandy loam. Back in October, I added composted sheep manure, perlite, biochar and wool pellets. So compared to prior years, the soil should be much improved now.

How many of the greenhouse plants are you planning to use for breeding, and are you selecting based on specific traits? cuz im planning to get some stuff from TSP, but idkk

Problem with seedlings, mottled brown spots on leaves

Problem with seedlings, mottled brown spots on leaves

CC57

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Problem with seedlings, mottled brown spots on leaves

Problem with seedlings, mottled brown spots on leaves

CC57

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Phyto

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Ninjadogma

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If you were a hotdog would you eat yourself?

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