Gardeners often ask us if there’s any danger associated with using too much of our Cascade Minerals soil builder product, made entirely of mineral-rich volcanic basalt.
There are two concepts to keep in mind in regard to this question. The first is solubility. The other is porosity, or structure.
Solubility
Finely milled volcanic basalt like that in Cascade Minerals is relatively low in solubility. The same cannot be said of man-made fertilizers which are highly soluble. It is this highly soluble nature of synthetic fertilizers that makes them such a liability if they are over-applied or misapplied. Excessive nutrient levels or poorly timed applications can result in injury to plants, contamination of the environment, and/or loss on investment.
Because volcanic basalt is so much lower in solubility—and because of its natural balance of nutrients—the risks of injuring plants or the environment are non-existent in comparison to chemical fertilizers.
Porosity/Structure
Plant roots need to be able to breathe and drink while obtaining the nutrients they need to grow. The porosity and structure of a rooting media determines root productivity. For example, if you took a bag of ground basalt and just added seeds and water the outcome would be disappointing because the roots wouldn’t have enough air to breathe.
The same effect is likely to happen if you cover your plants with 1-2 inches of rock dust without incorporating it into the surrounding soil. The volcanic material would likely suffocate the roots and soil. (Farmers that experience deposits of volcanic ash have to incorporate the ash into their existing soil because the ash itself lacks the structure for roots to thrive. The deeper the ash deposit, the deeper a farmer must plow to achieve the right mix.)
In short, when applied as directed and incorporated into the soil, there should be little to no fear about over-applying Cascade Minerals Remineralizing Soil Booster. On the other hand, more is not necessarily better. Once a sufficient dose has been applied to produce a beneficial plant response, adding more minerals is not likely to increase the magnitude of the response during the growing season.
