Ash preparation (pest ash)

What is the ash preparation?

The ash preparation — usually called “pest ash” or “ashing” in the biodynamic tradition — is a concept from Rudolf Steiner’s Agriculture Course (1924, GA 327, sixth lecture). Steiner describes a method of regulating pests that does not work through control in the usual sense, but through burning individual specimens and spreading the resulting ash in strongly diluted form. The idea behind it is, in Steiner’s wording, a “paralysis of the reproductive power” of the species concerned, brought about by returning the ash to the land.

The method is intended for animal pests (mice, voles, insects) and, in a modified form, for unwanted plants (weeds).

Steiner’s instruction

In the sixth lecture of the Agriculture Course Steiner gives a fairly detailed set of directions. For animal pests, one specimen is burned at a particular cosmic constellation — for mice Steiner names the time when Venus stands in the sign of Scorpio. The resulting ash is diluted further and further by trituration (“potentisation”) and spread on the affected land, either scattered or as a water spray.

For weeds Steiner describes a similar method using the seed of the unwanted plant, again under specific cosmic conditions.

Use and spread

In biodynamic practice the ash preparation is used rarely and cautiously. It counts as a sensitive concept, a method that moves within the biodynamic world between practical application and symbolic act. Maria Thun integrated it into her sowing-day surveys and kept constellation calendars with recommended times for burning; other biodynamic schools (Wistinghausen, Stappung) mention the ash preparation more reservedly.

At Demeter farm level pest ash is not a standard measure but an option that individual farms use — against persistent mouse infestation in storage, say, or during particular periods of insect pressure. Opinions on how well it works differ within the field; there are no hard studies.

Ashing the varroa mite

One much-discussed application is the ashing of the varroa mite in biodynamic beekeeping. The idea follows Steiner’s concept directly: varroa mites are burned under particular cosmic conditions, the ash is diluted and applied to the hives or the bees’ flight area. One clarification matters here: ashing is not a recognised varroa treatment, it replaces none of the established methods (oxalic acid, formic acid, drone brood removal), and under veterinary law it is not an application of animal medicine.