Button mushroom (champignon de Paris)
Agaricus bisporus
The button mushroom (Agaricus bisporus), grown for centuries on a compost of manure and straw, cellar cultivation par excellence, which takes up no space in the sun.
Role in permaculture
Closes the organic-matter loop: it turns manure and straw into food, then its spent substrate becomes an excellent amendment for the vegetable garden.
Growing this mushroom
- Method
- Fermented then cased compost (cellar cultivation)
- Substrate
- A compost based on cereal straw (about three quarters) and horse or other large-herbivore manure (about a quarter), fermented then pasteurised; a casing layer (a mix of peat and calcium carbonate) on the surface to trigger fruiting.
- Where to place it
- Grown apart, in a cellar, storeroom, cool basement, or a sheltered outdoor bed. The post-harvest substrate (mushroom-farm compost) is integrated into the compost and spread at the foot of nitrogen-hungry crops, tomatoes, squash, cabbages.
- Period
- In a cool cellar, storeroom, or basement, all year; in outdoor open ground, spring and autumn when the nights are mild.
- Level
- Intermediate
Steps
- Compost straw and manure (temperature rise, turnings), then pasteurise the substrate (traditionally around 60 °C).
- Once cooled (below 30 °C), inoculate with grain spawn.
- Incubate ten to twenty days at 20-24 °C, in high humidity, until full colonisation.
- Apply the casing layer; after the mycelium breaks through it, lower to 16-18 °C and raise the humidity to trigger the fruitings, harvested in several flushes.
Interest mainly nutritional (proteins, fibre, B-group vitamins), according to food composition tables. Like all agarics, to be eaten cooked.
Precautions
Always eat cooked. When foraging in the wild, the genus Agaricus exposes you to serious confusions: the phenol-smelling yellowing agarics (such as Agaricus xanthodermus, digestive upset) and above all, among young white specimens, the death cap and the destroying angel, deadly. In cultivation, the substrate being inoculated with a known strain, this risk disappears.
Sources: Myciculture.com, fiche technique de culture d'Agaricus bisporus · cultiver-les-champignons.com, culture du champignon de Paris et substrats compostés · TOOL Foundation (1986), La culture des champignons (série Agrodok / Agromisa), chap. 12 (nzdl.org) · Paul Stamets, Growing Gourmet and Medicinal Mushrooms, Ten Speed Press, 2000
Nutritional & medicinal properties
For educational purposes. Not a substitute for medical advice. Effects depend on the form, the dose and personal context.
Precautions & contraindications
Preferably eaten cooked. The raw flesh contains agaritine, a natural hydrazine derivative, largely broken down by cooking and storage; to date no proven risk to humans at dietary amounts has been demonstrated, but as a precaution it is reasonable to moderate large raw quantities. General recommendation (ANSES): do not eat mushrooms raw and keep to a reasonable quantity (≈ 150-200 g/adult/week).
Species & varieties
The best-known species and varieties in France.