All you need to stimulate plant growth is a little bit of primary rock powder. This is less of a classic fertilizer and more of a natural additive that is usually rich in silica, aluminum oxide, magnesium, iron, manganese, potassium and calcium. Important nutrients such as nitrogen, phosphorus and potassium are only found in small quantities in the finely ground rock. The aim of its use is primarily to improve the soil quality and water-holding capacity in the home garden – and thus automatically strengthen the plants. The primary rock powder is usually made from nutrient-rich lava rock, basalt or diabase, and more rarely from nutrient-poor rocks such as quartz, zeolite and granite. These are used to improve soil storage capacity.
Depending on what type of soil it is and which (weathered) stones and therefore minerals are already contained in it, the ancient stone flour can and should be used differently. For a rough overview:
If the soil is sandy, it is rather poor in nutrients and humus because the rain washes the nutrients out of the upper layers of the earth. Here the nutrient content can be increased with alkaline primary rock flour. However, if you use a flour based on bentonite, the formation of clay-humus complexes should be stimulated.
If the (peat) soil is rather acidic, the PH value can be raised and thereby neutralized with calcium-containing primary rock powder based on diabase. Afterwards, garden plants feel much more comfortable.
Primary rock flour based on basalt (or granite), on the other hand, is said to help acidify strongly alkaline soils that are particularly rich in lime.
Basic soils, such as lawns, should be supplied with nutrients by adding primary rock powder from lava or basalt.
If you want to improve the activities in your compost, it should make sense to use primary rock flour based on diabase or lava rock.
And another tip: If you are not sure whether the soil is acidic or basic, you can measure the pH value.
Since it is usually a fine to coarse-grained flour, the question arises as to how the primary rock flour should be used. Here you can choose between different methods, a few common ones are, for example:
Note: The fine powder releases a lot of dust, so it is advisable to wear a face mask during use.
As far as the correct dosage is concerned, as a rough guideline it is recommended to add up to 150 grams of primary rock powder per square meter of soil for calcareous soils and 200 to a maximum of 300 grams for acidic soils. As a rule, you will also find precise information on the manufacturer’s packaging. Since it is not a classic fertilizer, you cannot over-fertilize the soil. It is also important to know that the roots can only absorb the trace elements and minerals once the primary rock powder has been completely decomposed. Accordingly, you should not expect a short-term effect immediately after use.
As mentioned at the beginning, the primary rock powder can not only help to promote the growth of plants: it also makes them more resistant to pests. In addition, it is said to protect against fungal diseases. To drive away sucking insects such as aphids, it can be helpful to sprinkle the fine powder onto the affected areas – for example using a powder bottle. Snails, on the other hand, should be kept out of the beds by sprinkling the primary rock dust on the ground around the vegetables as a natural barrier (approx. five centimeters wide). To prevent plant diseases, pollinating the leaves can be useful in order to nip possible fungal spores – in the truest sense of the word – in the bud.
And one more tip at the end: If you make nettle manure, you can add the primary rock powder to neutralize the smell.
Sources: My Beautiful Garden, Utopia
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