The beds for growing the mushrooms having been made up, the spawn having been selected, the beds are ready for planting whenever the temperature has been sufficiently reduced and the material is properly cured. It is quite easy to determine the temperature of the beds, but it is a more difficult problem for the inexperienced to determine the best stage in the curing of the material for the reception of the spawn. Some growers rely more on the state of curing of the manure than they do upon the temperature. They would prefer to spawn it at quite a low temperature, rather than to spawn at what is usually considered an optimum temperature, if the material is not properly cured. The temperature at which different treatises and growers recommend that the bed should be spawned varies from 70° to 90° F. Ninety degrees F. is considered by many rather high, while 70° F. is considered by others to be rather low; 80° to 85° is considered by many to be the most favorable temperature, provided of course the other conditions of the bed are congenial. But some, so far as temperature is concerned, would prefer to spawn the bed at 75° F. rather than at 90°, while many recommend spawning at 70° to 75°. In some cases, I have known the growers to allow the temperature of the beds to fall as low as 60° before spawning, because the material was not, until that time, at the proper state of curing. Yet an experienced grower, who understands the kind of spawn to plant in such a bed, can allow the temperature to go down to 60° without any very great risk. Fresh spawn in an active state, that is, spawn which is in a growing condition, as may be obtained by tearing up a bed, or a portion of one, through which the spawn has run, is better to plant in a bed of such low temperature. Or, a bed of such low temperature, after spawning, might be "warmed up," by piling fresh horse manure over it loosely for a week or ten days, sufficient to raise the temperature to 80° or 90°. [Illustration: FIGURE 235.--Pieces of brick spawn ready to plant.]