Yellow leaves overnight

Can anybody help please?

I plant outside in fabric pots 7gallon organic soil.
Few days ago I noticed the lowest leaves on plants are yellowing at a fast rate.
The rest of the plant is doing good, nice dark green leaves.
Googling the most appropriate answers were these:

1.Root pH
2.Poor Watering Practices
3.Nitrogen Deficiency
4.Light Burn (no, growing outside)
5.Heat Stress ?
6.Magnesium Deficiency
7.Iron Deficiency
(Don’t apply 8.Not Enough Light (Seedlings) 9.Bugs or Pests 10.Bud Rot)

How do I narrow down the problem? I tested the water and it is 7.5pH
So I started to add lemon juice to drop to 6.5pH in water…

What about the other possibilities? Poor watering could be too, it’s been 27C to 30C and I am watering every other day in the morning.

I don’t know how to tell Nitrogen deficiency.
A couple of photos to show you. I would greatly appreciate any help on how to identify and treat the problem.

I have had a similar problem. I used a pen to make a little hole in the soil about 6in deep about 4inchs from the stalk. Slowly pour your ph water in there til you get runoff you can ph test. The reason for this is to get good runoff through your root ball don’t just stab the dirt do it slowly and wiggle it around you can use a Phillips screwdriver to. If your ph is out of wack flush with just ph water or use a flushing agent. Don’t forget to check and calibrate your ph meter to

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You want soil ph at 6.3-6.8 otherwise lockouts will occur
Ph up or down is best when adjusting ph
You should get a ph reading of your run off

And dont feed until you get soil ph under control


Thanks a lot for your advice, will do the pH testing ASAP.

I already know that the tap water (i use) is around 7.5 and can go up to 8.0 even, depending on the city water treatment program.

It (almost certainly) is over 7. So in your opinion this high pH water accumulation alone could be the problem?


Being in the wrong range will prevent the plant from metabolizing nutrients present in the soil as they are only soluble within a certain PH range. That happens to be (usually) between 6.3 and 6.8. If you are using strips or a soil tester, ditch them as they are worthless and buy a decent digital PH meter. The Apera PH20 is popular if a little more expensive than others.

The reason @Countryboyjvd1971 said no nutes is that when you water in range, the nutes already present will now be visible to the plant and you could end up with too much.

Your plant looks hungry to me which also points toward a lockout.


Wise words to you from the others. Spend $20 get a set of PH and PPM meters.

When feeding…take plain water ph n ppm reading. Add nutes…take ph n ppm reading.
Adjust ph until it is 6.3 to 6.8…allow to reach ambient temp then feed.
write this information down, helps track development and progress.

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Great advice and I appreciate it. THANKS.

I got Pancellent kit pH and PPM and I had them calibrated, just to make sure, because with my tap water reading was 7.5-8.0 pH and I thought maybe the meter is out of whack or I don’t know how to use it.

My store friends also advised me to get a bottle of Enzymes that help dissolving the PLANT ENZYMES.
WILL HELP CLEAN roots, providing better contact betwemen the root and the nutrient solution for better nutrient uptake.

I’m using great quality soil, so normally I shouldn’t have this problem.
Thanks, will report back.

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use quality nutes…start at 30% and adjust as needed.

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Could you be so kind and break it down for me please? I really don’t understand the 30%…

I don’t feed them, except for worm casting tea every other day.

PS. Now I make sure water is around 6.5pH, with help of lemon juice.

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Keep the ph in the 6.5 range youll see good results in a few days
Watch new growth the damaged leaves wont be repaired


Thanks Countryboy, I believe I already see some difference since few days.

I started seriously testing and phing water every time I water or make worm tea.

One more question, when you water, outdoor in fabric pots ONLY, how much water do you use per plant?
I water every other day, like ~2L or 1/2gal…in hot weather 28C/85F or so…
How much, “on the average” does a plant need per week?


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Faster----------mfg’s usually post a feeding schedule. either on the product, pamphlet or the website.

From personal painful expensive experience, I can tell you their feeding schedules may work with tomatoes, but, will burn most strains of weed.
I suggest that starting at 30% of what those feeding schedules state is A VERY GOOD IDEA.
Some growers say not to feed until 4 weeks. I start feeding at second set of real leaves.
And, adjust as the plants indicate.

Having explained that…is the planting media you are using fertilized? If so, it’s too hot.

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In fabric pots especially outdoors you want to water till you see run off 20 % or so what your putting in
Depending on how big they are they require more water and depending on how hot and dry the climate is also
I will water my pots outside almost every day once plants are established well

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Sorry, I’m thick as a brick…
I chucked the bags, but from memory, one was “bat mix” and the other Royal mix.
The BM went on the bottom of pot and RM on top, as recommended by the store and they said that usually adding nutrients is not necessary, except if I accidentally flushed the nutrients out.

I found the links to the soil I use. All organic etc…
I hope you understand my confusion about 30%…of WHAT?

Faster-----yes, the confusion is easily understood. I wrongly assumed, you were feeding nutes. This is a great place to ask questions.
Found this information which might be useful:
Description: plagron Royalty Mix is a light, airy, soil-based growing medium, heavily fertilised with an entirely organic composition.
Plagron Bat Mix is the finest highly fertilised soil that contains a generous amount of Bat Gua

Good luck with you Lady.

So I would bet that your city water has Chlorine in it… fill a bucket with your water and let it stand for 24 hours or toss a air stone in there to off gas the chlorine for a few hours… chlorine will prevent your plants from eating because it kills the organisms that feed the plant.

Your other issues are minor to chlorine killing your plants.

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