New leaves have yellow edges - Day 36


It’s day 36 and my new leaves are turning a little yellow on the edges,

Soil - Pro-Mix Potting Mix
Light - 5 100W Bulbs, closest one is 4" from plants - 18hrs under the lights
Nutrients - Last feeding May 11th (1/4 strength Green Planet Dual Fuel 1/2)

Soil was fairly dry to the touch, I gave her 1/2 cup of pH balanced water earlier today, moisture meter says 3/10 which is below the “Good” moisture reading.

Should I give her more water or wait?

My other 2 plants moisture reading is in the green is 5/10 and 6/10, they don’t seemed to be as affect, just slight yellowing


What is your soil? Have you taken runoff numbers for pH and PPM? Are you just watering? Frequency?Your plant should be much farther along at 36 days. Something is off.


Throw the moisture meter out. After you water, lift the pot and get a feel for how heavy it is when fully wet. Then, wait until it’s completely dry to the touch, at least a few inches down, before watering again. When you say “pH balanced,” what pH do you adjust to, going in, and what are you getting coming out? I agree with @WickedAle, something is way off if they’re 36 days old. Should have half a dozen nodes and be starting shoots in the crotches by now. No sweat though, they’re still mostly green, and upright. They will recover! :v:

Out of curiosity, what does your moisture meter read in a glass of water?


Pro-Mix Potting Soil
No runoff yet
Just pH balanced 6.0 water just when it gets dry finger knuckle deep

Balanced to 6.0
I leave them to get wet about an inch down then water. No run off yet.

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I had a problem like that and it turned out to be soil was to hot. I transplanted to different soil lower ppm and now plants are doing good

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Prefertilized soil is famous for burning plants. Best to mix with reg media or none at all.

Your babies look ok, but the slight drooping is a warning sign.


Pro Mix potting mix is an actual soil, not like the typical stuff people refer to as “pro mix” as in a soil-less medium. Your pH should be nearer 6.5. The size for their age and the drooping leaves lead me to believe they’re being overwatered, too. Let them dry out more and see if they look less droopy. Do you have a TDS meter to measure the PPM of the runoff, too?


Yes I do have a PPM Meter, I will let them dry out and then feed them some nutes and measure the pre and post watering/runoff

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Just to clarify today is Day 38 since Seed, which I believe makes it Day 31 of Veg Stage.

They sat outside in the sun today from about 7:00Am to 5:00PM, they are now under lights until Midnight.

Not sure if they are getting better or not, lack of experience. The soil is drier now.

Yeah, the tops look perkier already. :+1:

I’m wearing out the wheel on my mouse scrolling up and back, but yeah, they look better already, to me.

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LOL, thanks for the help, I will leave them another day or two.

Should I then water with pH balance (6.5) or nutes?

Just water first, and only in a ring around it at first, not to runoff. It doesn’t need very much yet. Once those first two round leaves, the cotyledons, have completely yellowed, there’s still a lot for them to eat in your soil. Once they have a few more sets of leaves, you can water to runoff and get a PPM reading and see what’s what from there. But for now, I’d just water @ 6.5 pH. Which soil is it again? The Pro Mix “potting mix” I’m seeing had a time release fertilizer in it. Can you post a picture of the bag?

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Better Yet, here’s manufacturer’s web page with the details.

I misunderstood which “Pro-Mix” to buy when it was recommend, and as a newbie, I had no idea there were different type of it.

No worries, I bought time-release fertilized perlite my first go. The fertilizer in it might be a problem once you’re ready to flower. It might be way too much nitrogen for the plants needs once they are flowering, and could burn them and hurt the yield. Maybe not. You may be able to flush the fertilizer out of it before you flip. They don’t give any info on their site as far as N-P-K numbers. The “up to 9 months” part bothers me though. Might need to transplant into something else when they’re ready. That mix may not be compatible with the needs of flowering cannabis.

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I will see if I can get the proper soil this weekend, and I should be looking for Pro-Mix HP?

That’s the ‘inert’ medium people usually refer to when they say “pro mix” I think. Are you aiming for a soil grow, or more hydro-leaning soil-less?

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