Biodynamic mushroom growing: substrate, Demeter requirements and preparations
How biodynamic mushroom growing works: biodynamic substrate, the Demeter requirements for raw materials and casing soil, and the use of the preparations after steaming – an overview.
Edible mushrooms such as button mushroom, shiitake or oyster mushroom can also be produced according to biodynamic principles. The difference from conventional mushroom growing lies less in the cultivation process itself than in the origin of the substrate and in how microbial life is handled: the raw materials must be of biodynamic origin, and after steaming the preparations are used to guide the recolonisation of the substrate. This overview summarises the main requirements.
The substrate: origin is decisive
The core of the Demeter requirement concerns the raw materials. Substrate components of agricultural origin — cereals, straw, manure — must come from certified biodynamic growing. It is recommended to produce the substrate on your own farm wherever possible, because this allows quality and origin to be reliably controlled and keeps mushroom growing integrated into the farm cycle.
If wood is used — for example oak logs for shiitake, chips or sawdust — it must not have been treated with insecticides after felling. Peat is permitted as a casing soil for button mushrooms, but ecological alternatives such as wood fibre are preferable in order to avoid peat extraction.
Steaming and the preparations
Substrates and soils may be steamed to reduce unwanted germs and competing organisms. What matters is what happens afterwards: so that the substrate is recolonised by desirable microorganisms, biodynamic compost preparations, aqueous compost extracts and horn manure or barrel compost are used immediately after steaming. The logic is the same as with compost: not just sterilising, but deliberately inviting life back in and guiding it.
Context
Biodynamic mushroom growing is a niche, but a consistent step in the farm cycle: mushrooms make use of organic residues such as straw and manure and at the same time provide a high-quality food. Anyone who wants to grow with Demeter certification follows the current Demeter standards, which set binding requirements for substrate, raw materials and methods.
Frequently asked questions
What must the substrate meet in biodynamic mushroom growing?
The agricultural components (cereals, straw, manure) must come from biodynamic growing; producing it yourself is recommended. Wood must not have been treated with insecticides after felling.
May the substrate be steamed?
Yes. After steaming, biodynamic preparations (compost preparations, compost extracts, horn manure or barrel compost) are used to guide the microbial recolonisation.
Which mushrooms are suitable?
Among others, button mushroom, shiitake (for example on oak logs) and oyster mushroom. The current Demeter standards are what count for certification.