nd ferment it during August and September, spawning
the beds in September and October. Others begin work on the fermentation
of the manure in June or July, make up the beds in July and August,
spawn, and begin to draw off the crop somewhat earlier. The second crop
is prepared for whenever the first one is drawn off, and this varies
even in the experience of the same grower, since the rate of the running
of the spawn varies from time to time. Sometimes the crop begins to come
four or five weeks from the time of planting the spawn. At other times
it may be two or three months before the spawn has run sufficiently for
the crop to appear. Usually the crop begins to come on well in six to
eight weeks. The crop usually lasts for six weeks to two months, or
longer.

=Productivity of the beds.=--One pound of mushrooms from every two
square feet of surface is considered a very good crop. Sometimes it
exceeds this, the beds bearing one pound for every square foot, though
such a heavy yield is rare. Oftener the yield is less than half a pound
for a square foot of surface.

=Causes of failure.=--The beginner should study very carefully the
conditions under which he grows his crops, and if failure results, he
should attempt to analyze the results in the light of the directions
given for the curing of the manure, its moisture content, "sweetness,"
character of the spawn, temperature, ventilation, etc. While there
should be good ventilation, there should not be drafts of air. A
beginner may succeed the first time, the second or third, and then may
fail, and not know the cause of the failure. But given a good spawn, the
right moisture content of the material at time of planting and running
of the spawn, the sweet condition, or proper condition of the curing of
the manure, proper sanitary conditions, there should be no failure.
These are the most important conditions in mushroom culture. After the
spawn has run and the crop has begun to come, the beds have been known
to freeze up during the winter, and in the spring begin and continue to
bear a good crop. After the spawn has run well, beds have accidentally
been flooded with water so that manure water would run out below, and
yet come on and bear as good a crop as adjoining beds.

=Volunteer mushrooms in greenhouses.=--Volunteer mushrooms sometimes
appear in greenhouses in considerable quantity. These start from natural
spawn in the manure used, or sometimes from the spawn remaining i