In my area we have heavy clay, calcerous with high buffered pH.

Iron isn't your problem, it is the alkaline soil. I have a simple solution for you that I suggested to another GWer in Texas where the soil and tapwater were 8.5ph ish. Results were nearly immediate in terms of renewed growth and bloom.

Add vinegar to your water and water well. This results in the water being of a better ph for nutrient uptake and the roots can then grab the iron from the soil.

She used 1 teaspoon (or tablespoon, I forget) per gallon of water. She used a ph test kit to determine how much to use to get the ph to 6.5. It isn't all that important though if you are only using 1 tablespoon or less with alkaline water/soil it won't be too acidic.

If you do this I would appreciate hearing about the results.

did buy green light 'iron and soil acidifier' which I can apply to the soil but is this organic?

Depends on what definition of 'organic' you wish to use. Plant nutrients are all inorganic minerals if you want to get really technical. Let's put it this way, the product is 'natural', but might be processed in some manner that would result in somebody considering it not organic, I don't know nor do I really care about the technical differences in such things.

You can certainly use it according to instructions without worrying about the microherd, in fact they will likely thank you for lowering the ph of the soil, but if the soil ph in your area is high then chances are so is the water. Adding vinegar to the water then consumes the buffers in the water so they don't make the soil alkaline again.

Let us know what you do and what the result are. Lowering the ph generally results in noticeable improvement within just a few days.

For watering our blueberry shrubs, during a drought, I have to add 6 fluid ounces of "grocery store vinegar" to 4 gallons of tap water. As you might have guessed, our tap water has lime in it, and will significantly raise soil pH if it is not acidified before application.

Holy Cow Eric, where in Dane county do you live? You don't have to answer that of course, but I ask because my wife's grandfather lives in Madison and has had very productive blueberry bushes in the ground for 25 years. He uses sulphur annually, but irrigates with plain tap water (when it needs to be done). Are you on a well or municipal supply?

Just curious, how did you determine it is iron chlorosis. Both manganese and magnesium deficiency cause interveinal chlorosis according to wisc.edu.

FWIW, I have never been pleased with the results of foliar feeding for chlorosis and I was not operating under the constraints of "organic". I just could not make it work.

Here is a link that might be useful: wisc.edu soils

House guests, so sorry for late reply:

I've been foliar feeding with seaweed extract, and not watering (soil wet enough) and the leaves are greening up a bit, could be the soil was waterlogged, or iron in the seaweed or that it's been warmer-probably the last.

I'll definately try the vinegar solution, but I know the soil itself is well buffered, so I don't expect much of a pH change from watering it, but I will try (when I next water). A nursuryman told me that we could pour pure muratic acid on our soils and the pH would bounce right back. But maybe it'll help long enough to get nutrients into the roots. I don't think our water is alkaline, I did pH test it a while ago.

Username_5

Don't you figure that an acidic shock with 'iron and soil acidifier' would kill a good bit of the current alkaline-lovin microherd leaving the survivors to repopulate and in the meantime the soil depleated in microorganisms and so less able to provide nutrients to the plant? I agree in the long term that's gotta be the way to go though, just that I want a few tomatoes this year. Good to know it won't hurt worms-I like those guys and they all just moved in.

Albert,

I based my determination on a couple things, course I could be wrong:

--Chlorosis is in new leaves and not on old growth.

--This is the best site I've found which shows pictures of each different deficiency. Plant Physiology Online: Visual Symptoms of Nutrient Deficiency In Plants

--Based on the pics, it most looks like the iron pic (but not as severe), the youngest leaves are showing chlorosis, not the older ones, and mostly at the center of the leaf stem.

--Manganese "They develop a light chlorosis along with gray specks which elongate and coalesce, and eventually the entire leaf withers and dies"-I'm not seeing any grey, and chlorosis not all over the leaves, not speckled looking either.

--Magnesium: "show advanced interveinal chlorosis, with necrosis developing in the highly chlorotic tissue" I don't see any necrosis, and not all over the leaves. Epsom salts (Magnesium sulfate) doesn't help either soil or foliar fed.

--It's really common in our area and TX in general

Hmm, thats a shame, I thought foliar feeding would work well. Article about iron chlorosis in texas that recommends foliar feeding

I read about some sort of iron chelated in sugar or something like that, instead of a synthetic (H)EDTA complex, but I don't know what the product is called or if its even on the market. Maybe I can just mix copperas-I can't find this though--with molasses + heat?

Username_5: My personal goal with organics is to grow my home vegies, without synthetic or toxic pesticides, without causing a runoff problem or fish kills(I grew up on a lake in FL that had at least biannual fish kills resulting from runnoff and algal blooms that infected an entire lake chain whenever they fertilized/or whatever-I can't be even a small part of this if I can prevent it), while encouraging beneficials and soil health--all this to my best ability. I understand the chemical deffinition of organic/inorganic I ment organic with respect to the above.

Don't you figure that an acidic shock with 'iron and soil acidifier' would kill a good bit of the current alkaline-lovin microherd leaving the survivors to repopulate and in the meantime the soil depleated in microorganisms and so less able to provide nutrients to the plant?

No, it isn't going to harm the microherd. Soil acidifiers can take 1-2 years to have any significant effect on overall soil ph. Attempting to alter soil ph by more than a point is usually very difficult and it sounds like your soil is strongly buffered. This is why I usually don't bother trying to adjust soil ph, I just adjust the ph of the water used to irrigate. It is the water that will surround the roots and until the soil buffers neutralize the acid the roots are then able to better uptake nutrients.

Rain has a ph of 5 assuming 0 pollution. With industrial pollution in the air a ph of 4 isn't unheard of. Vinegar has a ph of 3. Mixed with water the ph goes up. The idea behind using vinegar in water is simply to make it more closely approximate rain.

Therefore tapwater with vinegar is no more likely to harm the microherd than rain is.

Additionally while plain household vinegar (white,distilled) is well suited to this use, you might enjoy exploring the world of vinegars. Many of them are incredibly nutrient rich.

Sulfur is antibiotic. Even molasses should be the unsulfured variety when used in a foliar mix.

If your soil test indicates that the soil needs trace sulfur, it should be applied in the sulfate form, e.g. iron sulfate.

Terran