Test crops
Portabellas
Scam 

Agaricus mushroom cultivation began in 'caves' (actually underground galleries where limestone had been quarried), moved into sheds, stables, and greenhouses, and today is generally carried out in large, purpose-built, climate-controlled buildings.  Globally almost two billion pounds of mushrooms are cultivated annually.  The farm gate value of the crop is more than $1,000,000,000.00, and the retail value is several times that.

Whether on an industrial scale, or as a hobby, Agaricus cultivation consists of a few main steps.  These can be complex and require a certain amount of artistry.  A good reference is essential.  Briefly;

1. A high nitrogen, straw-based compost is prepared
2. The compost is pasteurized and finished at an elevated temperature
3. When cool, the compost is mixed with pure-culture mushroom spawn
4. The mushroom culture (= mycelium) grows through the compost in 2-3 weeks
5. A 'casing layer' of clean peat moss or soil, with limestone, is spread on the top of the compost
6. As the mycelium grows into the casing layer, over about 15 days, the grower uses air, water, and temperature to cause tiny mushroom 'pinheads' (= primordia) to form
7. Mushrooms quickly develop and after a few more days can be picked weekly for three or more weeks

This method works for several species of Agaricus, but most are slower than A. bisporus, and some require different composts, casings, and environments. 

Museums of mushroom cultivation can be found near

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