Citrus iron deficiency or something else?

Thank you all for your expertise!

@disc4tw @Vlad - I have been using a cactus/citrus soil blend that drains really well so don’t think its an issue. To be sure, I did lift it out and roots look healthy creamy/yellow and takes up about 60% of the pot volume.

@ZinHead - I ordered citric acid. Do you still recommend adding despite absence of root rot? what concentration and frequency? Anything else in terms of micronutrients or conditioners in ! setting of good aeration already?

@bigiggye Your roots look fine but your mix looks very water retentive. Commercial cactus/citrus mixes generally are too water retentive. If you are not having root rot, you will later. I suggest you use a 5:1:1 mix, which is what many people use. (5 parts pine bark:1 part Perlite: 1 part peat moss.) Or Al Tapla’s gritty mix.


Yep, because Citric Acid helps chelate micronutrients.
I just read the SDS ingredients safety data sheet on the fertilizer:
Monoammonium Phosphate
Potassium Nitrate
Monopotassium Phosphate
Magnesium Sulfate
Boric Acid
Copper EDTA
Manganese EDTA
Ammonium Heptamolybdate
My analysis:
Monopotassium Phosphate precipitates (Iron EDTA) into Iron Phosphate which is not water soluble.
Magnesium Sulfate will unchelate poor quality Iron chelates like Iron EDTA into Ferric Oxide which is not very water soluble.
Epsom salt increases the need for Iron too.
Increases in (Copper, Zinc & Manganese) combined with high Potassium at a time when Iron is being precipitated is the problem.
1 teaspoon Citric Acid
1oz Gypsum
(1/4) teaspoon of Iron-EDDHA which won’t precipitate!!!

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Always use Iron-EDDHA as the iron source!


Re-Read your original statement again.
Azomite has very different results on different varietals & species.
It varies in pH from (8.0pH to 8.5pH)
This reduces Iron availability especially with Iron EDTA.
It also has a lot of water soluble Aluminum & water soluble Silicates.
It can cause Aluminum (& or) Silicone toxicity!!!
What type of Iron foliar???
Citrus have very water tight leaves which don’t absorb foliar sprays well, especially when Potassium is high.
As that makes leaves smooth, glossy & water tight.
Iron-EDDHA can be sprayed on branches & nodes, plus put in the soil.
Spraying leaves doesn’t work well on Citrus.


Wow, thanks @ZinHead, I am blown away by your knowledge and grateful that you’re taking the time to share. Do you have a chemistry/agricultural science background? I am confused why the company would formulate such a fertilizer mix if half the salts precipitate out, and why this only seems to be a problem for 1 out of 3 trees with identical rootstock.

The iron I have is HEDTA, and since pH is around 6, it looks like only half is bioavailable, so I plan on doubling the rate you recommend. Have the citric acid and gypsum coming tomorrow.

Thanks again.

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My career was as Environmental Services Director for hospitals, Nursing homes, school districts, military base etc.
My OCD hobby has been agronomy research & plant breeding.
So I have extensive topic knowledge in chemicals, microbes, photosynthesis, symbiosis, quorum sensing, pathology, etc.
I’m far from an expert in any one topic as I’m self educated.
However, I have far better understanding out how different things interact.
I generally use a computer to scan scientific research articles for key words & then only read what is relevant to my interests.
I highly recommend Iron-EDDHA.
Also you can mix (1/4) teaspoon per gallon of Glycerin into the solution with the Iron-EDDHA.
It will help the solution enter plant cells.
Even though Glycerin is a 100% natural organic plant based product, do not go over (1/4) teaspoon.
It increases the water solubility of Boron & Auxin.
Too much can causes imbalances in nutrient & hormones.
And always best to spray branches!
Most fertilizer products are messed up in one way or another.
It is the rule, rather than the exception unfortunately.

Feel free to tag me on other topics.
Even if I don’t know the answer, I usually know who would know the answer.
I make it my top priority to have good mentors!!!
A pleasure to have been able to help.

Thanks Vlad, I want to follow your advice but have some follow up questions. There are tons of different types of pine bark products - do you mean something like this?

Do you think it’s worth repotting now, with better draining soil - I did repot it with additional perlite after pulling the plant out to take the picture a few days ago. I don’t want to keep disturbing the roots, and maybe giving time for the citric acid/gypsum/iron to work like Zinhead suggested. Alternativelty, I can wait till the fall as we are getting into the dry season here in Ohio, and I can ensure soil properly dries out before watering again.

Does pine bark do something that perlite doesn’t?


The Home Depot pine bark is fine, but expensive. I get my pine bark (fines) mulch from Agway. This is what it looks like:
I sieve it through a 1/4 inch screen.
I would wait one month before repotting to let it recover. Do not wait until the fall because you want it to be still in growth mode.
Pine bark fines retain more water than Perlite.

@bigiggye your soil analysis indicates:
Magnesium, Copper & Iron levels very high.
Phosphate & Boron is low.
The fertilizer you used is high in:
Copper, Magnesium, Sulfate & Potassium.
All 4 of which if too concentrated interfere with Iron assimilation.
While your native soil is the correct pH,
Ohio water is 8.5pH to 9.0pH which keeps Iron in a Ferric Oxide state which is not very water soluble.
The correct procedure is:
MonoCalciumPhosphate aka TripleSuperPhosphate to counter act Magnesium, Potassium & Copper.
Gypsum 7.4pH to supply Calcium
Iron-EDDHA to have water soluble Iron.
Borax Glycerinate drop per gallon as foliar to improve Calcium & Iron assimilation.
This will correct the problem faster than anything else.
Far faster than organic material.
Yet will only be effective on new leaves.
Old leaves have too much (Magnesium, Copper & Potassium) combined Calcium deficiency.
So no matter how much Iron the plant gets those leaves can’t achieve good health.
Only new leaves will exhibit balance.
Calcium can only be assimilated by stem cells & juvenile cells.

@ZinHead You said “your soil analysis indicates”. What soil analysis? I could not find the poster’s soil analysis. Please show me it.


I’m not going to post what another member sent me in a private email.
If @bigiggye wants to post his soil analysis or email you it, then he can.
Or he can give me permission to post the portion where I highlighted the Magnesium & Copper levels.

Yes, since zinhead appeared to know a lot about soil chemistry, I sent him a private follow up question regarding a soil analysis of my backyard orchard, which is unrelated to the potted citrus in this thread. I am waiting to see if the citric acid, gypsym and iron do anything.

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If (Magnesium & Copper) are high in the soil,
there are most likely high in the City water supply too!
So please don’t assume that they are unrelated.
Your fertilizer which you claimed to have given the citrus was also high in Magnesium Sulfate, Potassium Sulfate & Copper.
Too much Sulfate also interferes with Iron assimilation in citrus.
I’m on 2 separate post threads here where Sulfate is involved in Iron deficiency.
It’s not a coincidence!

Planet Earth is 35% Iron.
Most is not water soluble.
Plants only need a few parts per million of Iron.
Yet for most C3 Carbon Fixation Photosynthesis plant species it must be organic Iron.
In my research I have identified more than 3 dozen common things which interfere with Iron assimilation!
In this situation it is a synergistic interaction between 4 of the 3 dozen.
Too high of water pH.
Too much Potassium Sulfate from fertilizer
Too much Magnesium Sulfate fertilizer & water.
Too much Copper fertilizer & water.
Citric acid 3.2pH at 1 teaspoon per gallon of water will help.
I suggest reading that other thread.
Lots of similarities.

Straight pine bark is known to remove Nitrogen from soil environments. Cured conifer bark (e.g. orchid bark) is a better investment. Ag suppliers (not big box stores) sell it in 3 cu.ft. bags.

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@Richard You said “straight pine bark is known to remove Nitrogen”
Would using pine bark fines still be a problem if one fertilizes?

After this comment, I spent a lot of time reading about container soil and read the articles by Tapla. It really improved my understanding of how water and soil interact, capillary pressure and gravity creating a perched water table and how soil particle size impacts this. Thank you.

It’s only been 2 weeks, but adding the perlite seems to be making a difference. I am having a difficult time finding pine bark fines, but according to: Growing Citrus redwood shavings would work just as well.

I am still a little confused why bark/shavings is necessary though, can’t I just add more perlite till the drainage is ideal?

Do you use the same 5:1;1 mix for figs, or just citrus?

@bigiggye For figs, I use a 2:4:1 (pine bark - not sifted, peat, Saf -T-Sord or Perlite, 1 cup lime/5 gal mix) because it is more water retentive which is what figs require.