Looks like an off-the-shelf 5-1-3 organic fertilizer containing the needed micro-nutrients for citrus does not exist. There do appear to be some formulas that get pretty close on their own or in combination:

Neem Seed Meal: 5-1-2
Fish emulsion: 5-1-1
Greensand: 0-0-3
Liquid Kelp: 0.5-0.2-17
E B Stone Citrus & Fruit Tree Food: 7-3-3

I'm interested in hearing from other organic citrus growers using any of these (or other organic) fertilizers alone or in combination.

I use Gro Power's Citrus & Avocado Food. It is organic, and one of the very best products I have used for my citrus and avos. I like it because it has a very significant amount of humus and humic acids, as well as a soil penatrant, which for me, on my thin DG soils is very helpful in getting the soil microorganisms "doing their thing", as well as helping with micronutrient absorption and getting past that hardpan that can develop. It is 8-3-8, and here is the list of components:

40% Humus, 8% Humic Acids, Controlled Release Nitrogen, 6% Phosphoric acids (P203), 8% Soluble Potash, 4% Magnesium, 4% Sulfur, 2% Iron, .05% Manganese, .05% Zinc (our two micros most likely to be low in our S. Calif soils) and soil penetrant (1.00% Alkyl Naphthalene Sodium Sulfonate).

http://www.gropower.com/home_garden/consumer_products.htm

I am considering, though, switching to their High Nitrogen formulation, though, as it is closer to the 5-1-3 formulation, and still contains all the same amounts of micros, humus and humic acids as well as a soil penatrant. And, I should be able to use less, and it is more concentrated. Always a plus when you have a lot of trees to fertilize.

That formula is just theory.
In fact citrus do not need THAT much nitrogene, at all in organic cultures.

Of course you can PUSH growing rate and crops, but I think quality goes before quantity.

Neem Seed Meal: 5-1-2, I would buy (if available), for such seeds crack down slowly and nutriate micro organisms very good, contain lots of minerals and trace elements and that neem is the best natural pesticide as an extra value ...

No, this is not theory. The NPK requirements for citrus have been very well studied, Sanguinello. No matter how you decide to provide it, by organic culture, organic fertilizer or inorganic fertilizers, citrus still are best fed and will perform the best with a 5-1-3 NPK ratio. "Biology of Citrus", by P. Spiegel Roy and E.E. Goldschmidt, page 145, Table 5-7, Leaf Analysis Standards in Florida demonstrate that 5-1-3 ratio. "Assessments of nutrient deficiencies and toxicities" section goes on to explain how and why this was determined, and mentions a well respected and replicated statistical method call DRIS (diagnosis and recommendatoin integrated system) for evaluated leaf analysis results in order to formulate fertilizer recommendations. This is not theory, this has been successfully replicated thousands of times within citrus research. I quote only one of many scholarly references on this subject.

You can try to provide that by providing compost or organic materials (leaf mold, composted manure, etc.) with that NPK ratio (good luck with figuring that out), or by choosing to provide that with a fertilizer where you know the NPK ratio as well as percentage of the various key micronutrients. Neem Seed Meal does not contain needed micronutrients. Not all soils have the ideal ratios of micronutrients citrus require for optimal growth, so supplementing will provide your citrus with what the need for proper growth and fruit development and production. I know that my soil is lacking in both Manganese and Zinc, for example. And, my soils are very lacking in organic materials, I'm on nearly pure DG (decomposed granite). Great for growing succulents and figs, a little thin for citrus. Please provide your scholarly resources that support your comments around citrus not needing "that much nitrogen" in organic cultures, and define "organic cultures". We have an obligation in this forum to provide accurate data, I think.

Sanguinello wrote:

That formula is just theory. In fact citrus do not need THAT much nitrogene, at all in organic cultures. Of course you can PUSH growing rate and crops, but I think quality goes before quantity. Neem Seed Meal: 5-1-2, I would buy (if available), for such seeds crack down slowly and nutriate micro organisms very good, contain lots of minerals and trace elements and that neem is the best natural pesticide as an extra value ...

Scholary is a conception of the Mediavale/Dark Age.

Modern science is always on progress and all knowledge and evidence are changing all the time.

You are next to an orchard, that is NOT managed and the trees get NO fertilizer, not even water.
Nevertheless they have wonderful crops.
So how is that possible ?

By the way, we have also DG on some areas in Austria and we know for long that this soil is one of the best and brings exceptional quality crops.

Check out this pdf about using organic materials for soil amendments and fertilization:

http://cmg.colostate.edu/gardennotes/234.pdf

Personally I'm going to try a combination of alfalfa pellets, corn meal, seaweed, and spirulina.

I think that would provide ideal organic fertilization, soil improvement and disease prevention for citrus. I'll post results end of the year hopefully.

Thanx Lemandarangequatelo !

I use Guano from Peru.

I am next to an orchard that is dying, Sanguinello. The only reason the small oranges (not standard size, due to lack of everything) are good is because they are water-starved, which is causing them to be sweeter. The orchard now is about 3/4 to 7/8 dead. The only trees still surviving are the ones planted in the area of the orchard where the water naturally drains. Those will eventually die, too. The trees are not in good shape, and the trees are not producing anywhere near as well as they would if they were cared for. The only reason they have lasted this long, is they were very, very well cared for, fertilized, treated for pests (organically, I might add, this was at one time an organic orange orchard), and the trees were very mature and healthy.

I agree, science is always evolving, and we learn more and more as we go along. That still does not negate the fact (and not theory) that citrus will do better if fertilized in whatever manner you deem desirable, and in the ratios the trees need. Ancient societies had that figured out when they started dumping composted animal manure under their trees thousands of years ago. We slowly, and through science, were able to determine what is the most desirable ratio of nutrients for citrus.

And yes, DG is great for certain plants, and a little thin for others. So, I top dress my citrus trees with compost to increase the organic materials. The citrus, being higher nitrogen users, appreciate that. I don't do that for my figs, they don't need it so much, and love being in my DG. Just like they do in Italy.

Sanguinello wrote:

Scholary is a conception of the Mediavale/Dark Age. Modern science is always on progress and all knowledge and evidence are changing all the time. You are next to an orchard, that is NOT managed and the trees get NO fertilizer, not even water. Nevertheless they have wonderful crops. So how is that possible ? By the way, we have also DG on some areas in Austria and we know for long that this soil is one of the best and brings exceptional quality crops.

aha, so I misunderstood.
I just read about the great fruits ...

anyways I am sure they die just for the lack of water and not of fertilizer
I saw many orchards in Italy who did better when were left alone, than before ...

The orchard will die due to lack of water. It has declined due to lack of nutrients. The trees would survive if watered, but would have a shorter lifespan and not produce as well without additional nutrients. Will citrus grow without fertilizing (in my area)? Sure, as long as they get water. Will they be their best? No. I view my citrus trees as an investment, and like all my investments, I "invest" in them.

Why not buy it ?
Should be a good investment

The air we breath is about 80% nitrogen. Nitrogen is one of the three main components of fertilizer.N , P and K. If those three elements are not naturally occurring you must provide them or most all plants will not trive. You can get a little N from snow fall or thunder storms ( rain ).Too much or too little of each element is detrimental . N does not stay in the soil very long. It leeches out , down and up. It needs to be replaced. If not supplied in some fashion you will have unfortunate results. I assume cactus and other desert are an exception. Citrus is not. Tom

Well, if that is true, citrus could never grow in the wild ...

I think citrus would not grow or thrive in the wild unless it had very unusual natural occurring conditions favoring its growth in that particular location. The soil could have most needed elements occurring naturally and it could get some Nitrogen the same way. For example natural composting going on in the woods where some citrus might survive. Maybe even the rain forrest.....Tom

The Gro-Power Hi-Nitrogen 14-4-9 looks like a good fertilizer, but doesn't appear to be fully organic.