The above illustration shows how an ordinary cellar may be fitted up either with beds on the floor or arranged in tiers, one above the other, in order to increase the growing surface.
SPAWNING
The bricks of spawn should be broken into ten or twelve pieces and placed on the surface of the beds 8 to 10 inches apart each way. Then go over the bed again, raising the manure and burying the spawn about half-inch below the surface and tamping (pressing) firmly over each piece, leaving the bed level on top.
In about two weeks dig up a piece or two of spawn carefully, and if the mycelium is noticed running out like a mould from the brick into the manure it is time to case.
This is done by putting one inch of sifted soil evenly over the top of the manure.
VENTILATION
Where mushrooms are grown on a large scale, proper ventilation is very necessary. The overhead ventilators are generally preferred, as the ventilation is more uniform without draught.
The ventilators should remain open when outside temperature is right, and at other times for one or two hours each day.
Where small beds are used in cellars or out-buildings, extra ventilation is not so necessary.