Jack Herer Seedling Lower Leaves Yellowing

Hi all.

Jack Herer seedlings about 3 weeks old.
Indoor, LED light, no watering just dome misting, around 26 deg Celsius.
Soil seed raising/cutting mix together with perlite ~40%
See pics:
Lower leaves going yellow, one of them has black spot developing (red arrow).
In fact cotyledons gone brown & died a while ago.
But upper leaves still growing new ones.

What could the issue be?
Should I trim off the crappy looking leaves?


Forgot to mention 18/6 light schedule.

It’s ready to be watered and fed

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My first thoughts would be dry roots at 3 weeks in and only misting. And wrong npk ratio in soil mix.
It says that it feeds for 3 months on the lower left of bag.
Couldn’t find the npk in a quick search.

Outa likes but @PharmerBob beat me to it. :point_up:t2::point_up:t2::point_up:t2: :grin::+1:


@Oldguy I seen you replying and knew I could beat you :wink:

So long answer is @Oldguy is correct

Water first to see if soil will give the nutrients the plant needs to stop the yellowing.

Plants need roots, roots need water /nutrients

Wait a day or two and if the yellowing gets worse and moves up the plant. Lightly feed


That’s when I was trying to find the specs. :joy::joy::joy:

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Those crappy leave are the cotyledon, they are formed from the plant sprouting from the seed and can tell you a great many things if you watch them carefully

They will tell you, if watering correctly, when they plant could use nutrients for your first feeding. Try to keep an eye on those for future grows.

Also get rid of the Scotts soil and pick up some coco coir, or fox farm soil. Fox farm will have little - a lot of pre mixed nutrients. Coco coir will give you the ability to start with a clean slate or no nutrients

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Couldn’t agree more. Solid advice. :+1:
Happy frog is an excellent starter. :v:

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Thanks all for responses!

I would love to get my hands on Fox Farm , but unfortunately cant find it in Aus so I may have to build a suitable soil from scratch.

Also forgot to mention I am using distilled water (using a home distiller) for the misting & will also use it for future watering.
Q/ Is watering from the bottom tray a good idea? i.e. pouring into the tray & having the soil suck it up?

@granulat ,

I see you joined us in Sept. So with that…
Welcome to ILGM and to our community of awesome fokes
Ok, see that mix you have used, I posted a pic of the N.P.K All 14s that’s kinda high for seedlings. and then what you are adding + NUTRIENT BURN Plus the fact they are only 3 weeks old. I would just water for about two weeks then just add half the nutrients,
And while you are add it, lower that light a bit. See how she is getting tall. She is reaching for that light.
I’ll be watching.

B Safe


@granulat. [quote=“granulat, post:11, topic:38307”]
Q/ Is watering from the bottom tray a good idea? i.e. pouring into the tray & having the soil suck it up?
Short answer. No.
Pots should be elevated so they don’t sit in the wet.
Roots will stay too wet and cause all sorts of problems.
Cannabis likes a wet to dry cycle for watering. :+1:
And also I forgot to welcome you as well. :wink::v: Welcome to the best grow show on earth. :grin::wave::wave::wave:


Thanks Will, but I don’t think that’s the product I’ve been using.
This is the link for the product description of the Seed Raising/ Cutting mix I’m using:

but unfortunately it doesn’t mention NPK ratios there or on bag.

Thanks for lighting tip I’ll adjust it.


Thanks for that.
I actually was planning on adding just enough in the tray so it sucks up dry within an hour without sitting in the wet, I’ve done it with other herbs.
But to be safe I’ll just water it from above in a circle away from the stem.


My N<P<K is on the back of the bag bottom left…it really is a big thing and the way you are going to water is a good thing


Don’t forget to PH your nutrients after adding everything in!
6.2-6.5 for soil. Happy growing.


Hi again guys, got a problem that sprung up.
I’ve been using a clear pot - I should have covered it up.

When I took it out of the tent into normal light - I now see that there are a few moldy spots (or algae?) on inside of container - see pics.
Patches of green/brown

Is this fixable?
Should I transplant & remove those bits?

Transplant, or spray paint black. The algae will die when in the dark. @granulat

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Thanks for that.
I’ve since cut those bits out with a boxcutter, then covered the whole outer area with duct tape.