But, you can still grow organically in coco coir and the coir itself might even be listed. Of course you could use any chemical/synthetic nutrients in any kind of soil (or other medium), whether it was 'organic' to begin with or otherwise.
The first problem here is that many people have kind of specious, or less than accurate notions as to what 'organic' actually means as pertains to agriculture and home gardening. The next problem is what we consider to be 'soil'. Actual soil consists partially of disintegrated rock and minerals (sand, silt, clay), as somebody previously mentioned. The basic organic component of soil is humus: decomposed/decomposing plant matter and animal wastes, the result of microbial activity and other living organisms breaking those materials down. The most basic, good quality earth provided by nature is referred to as
loam.
The bagged potting soils that we buy for gardening purposes do not typically contain any soil or humus at all. They are composed entirely of other materials like sphagnum peat moss, coir, tree bark, perlite, vermiculite, etc.
Real soils begin with humus and loam, amended with other ingredients like sphagnum and perlite to enhance porosity and water retention characteristics.
For example, Ocean Forest is a
real soil. It contains: humus, sandy loam, sphagnum peat moss and perlite. The other ingredients are organic fertilizers: earthworm castings, fish emulsion, shrimp & crab meal, bat guano, granite dust, kelp meal, and oyster shell (adjusts pH and a source of calcium). It fully supports beneficial bacteria, symbiotic fungi and other micro-organisms (some of which come from the earthworm castings) until any synthetic nutrients, chelating agents or pH Up is applied.
Compare this to Miracle Gro Organic Choice Potting 'Mix': composted bark, sphagnum peat moss, poultry litter (pasteurized), organic wetting agent.
Most of the commonly available potting 'soils' are just sphagnum peat moss with perlite, dolomite limestone and synthetic fertilizers: urea, ammonium phosphate, monoammonium phosphate, potassium nitrate, potassium chloride, potassium sulfate, etc. Again, not
really truly actually soil at all!
If you find a 'soil' (or whatever the hell it is) and you think it's pH is too high, it isn't very difficult to lower it. You could just add more sphagnum peat moss (which is acidic) without any dolomite lime or oyster shell (which would raise the pH some), or buy some soil acidifier or pH down.