The use of rock powders in horticulture has a long history. Julius Hensel published his book, Bread From Stones, in the 1890s.
In 1924, Rudolf Steiner, the father of biodynamic agriculture, a method of organic farming, delivered eight lectures spelling out the failures of chemically intensive agriculture decades prior to the fallout in human and environmental health. Steiner described the esoteric knowledge of rock powders, and their ability to transmit cosmic life forces into the soil.
According to Steiner, it is the cosmic life forces emanating from near and far planets in the solar system and transmitted by rock powders that account for the ability of rock powders to radically stimulate soil microflora.
Today, information about the usefulness of rock powders is somewhat absent from the organic gardening community, even though areas in the world that have highly mineralized soils are prized for their exorbitant fertility, typically near active or inactive volcanoes.
Steiner highlighted three main types of rock powders: silica, clay and lime. Each rock provides a varying amount of minerals depending on the source and carries with it a specific energetic component, or subtle energy field, depending on the source of excavation, mineral content and paramagnetic measure, all of which impact soil energy and dynamics in varying ways.
For example, basalts with high silica content tend to be highly paramagnetic (have a positive susceptibility to magnetic fields), and the conductive property of silica allows for the transmission of spiritual energy into soil, and therefore the food that is produced.
This is important, as high-vibration, minerally dense foods act chemotherapeutically in the human body, detoxifying, cleansing and preventing disease.
From a traditional scientific standpoint, there is no doubt that the range of minerals has a dramatic impact on soil biology. Granite or basalt rock dust can have between a dozen and 100 unique minerals available to soil biology.
Both beneficial bacteria and mycorrhizae actively digest these minerals, breaking them down to a form usable by plants. The benefits of rock dust in altering soil fertility are innumerable: increased cation exchange capacity, improved soil structure, increased drought or frost tolerance, and increased resistance to insect pests, to name only a few.
Immediately, skeptics charge that plants have no need for this spectrum of minerals, as those necessary for growth number under 20 or so. But key to the use of rock powders is that minerals, many not necessarily drawn up by plants, are used in enzymatic processes—the biochemical catalysts of life—and also by micro-organisms in ways we yet little understand.
The minerals act as co-factors encompassing the multitude of enzymatic activities, and if not available, the entire metabolic process breaks down. This results in a harvest devoid of vitamins, phytochemicals, enzymes and minerals.
Rock powders are easy to use and typically can be applied without a soil test. Application rates vary widely depending on type of rock powder available, but generally rock powders are non-burning.
They are fantastic as a compost accelerate, or added to compost teas. I’ve witnessed the rapid colonization of beneficial bacteria and mycorrhizae growing directly on rock powders after adding inoculants, sugar and water.
I highly recommend including more rock powder-derived clays and minerals in your indoor soil blends. Note that rock powders are not compatible with chemical N-P-K fertilizers, and if combined, the benefits that rock powders usually provide will be neutralized.
The use of rock powders in hydroponic systems is a burgeoning field, but I encourage experimentation. The efficacy will vary based upon method and substrate, but ultra-fine rock flours passing through 200-micron screens are a great place to start. These are highly bioactive and will supercharge any growing environment.
I refer to rock powders as the kundalini of soil—the origins of soil energy.