Vegetable garden: growing button mushroom

Button mushrooms are grown mainly in cellars. Compare to other plants, the button mushroom has no root, no leave or flower. Cultivating button mushrooms requires carefully controlled atmospheric conditions. The mycelium (a mat of fine filaments) needs to be spread on natural manure (fermented and pasteurised horse manure) or artificial manure (mixture of hay, straw, bark, gypsum, potash and corncob).
Harvesting takes place when the mushrooms are firm and have a nice white colour.