What is the biodynamic preparation Horn Silica (501) all about?

Published by Tamara Harrison - 3rd Feb 2020

Winemaker Derek Hooper from Obelisk Wines‘ cellar door is always in full swing around summer. As a biodynamic winemaker, Derek gets asked a lot of questions relating to biodynamic practices. Here he is to chat about Horn Silica or 501.

What is Horn Silica or 501?
Basically, it is a clear quartz crystal (silicon dioxide) which is crushed into a very fine powder.

Why we use it:
Everything active in silica-like substances contains forces that do not originate with the Earth, but rather with the so-called distant planets – Mars, Jupiter, and Saturn. These planets are working through the siliceous to bring in the qualitative elements such as flavour, aroma, and form. ‘ Rudolf Steiner in ‘Agriculture’

How we use it:
Crush clear quartz crystal. Then grind very fine powder. Mix with spring or rainwater to a consistency of dough. Pack this mixture into cow horns. Bury in the ground during spring and summer. One horn produces 300-500 grams of 501, enough for 150 to 250 acres!

When do we use it:
Lift the horns in Autumn. Dry in sunlight. Store in a glass jar. Keep in a light, sunny position. The spraying method is the same as for 500. The best time is just before sunrise. Spray at seeding stage and before harvest. Do not spray in strong wind. Misting spray into the air is preferable.

Whilst 500 enlivens the feminine pole of Earth, matter, and darkness; 501 enhances the opposite masculine pole of Sun, form, and light. The 501 is mixed and sprayed out into the air early in the air when the mist is rising or dew evaporating.

In Layman’s terms, this is why we use it:
Horn Silica (501) can be considered as a sort of “spray of light” that promotes plant vigour, and reins in excessive growth. It adds a crystalline, luminous quality to plants, and reduces their susceptibility to diseases.
501 is applied in spring at the onset of the vines’ leaf development, and in summer to stimulate optimal fruiting. 501 enhances the effects of warmth and light on the plant to promote healthy growth. By stimulating photosynthesis, it works to increase the vines uptake of nutrients.

With regular applications, 501 assists with:
· Better photosynthesis
· Stronger root exudation and nitrogen-fixing
· Healthy, stronger, balanced, more compact and resilient leaf growth
· Better expression of genetic material
· Protection from certain diseases
· Robust flowering, fruiting, and ripening
· Raising the Baume level in fruits
· Improved flavour and nutritional value in fruits

I hope this explains the reason why we use it!


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