35 



evident that in many places mushrooms may not be grown as a sum- 

 mer crop. With artificial heat they may be grown almost anyivhere 

 throughout the winter. Moreover, it is very probable that in this 

 country open-air culture must be limited to a few sections, and re- 

 stricted, commercially at least, to a single season. 



A second important factor is that of moisture. The place should 

 not be very damp, or constantly dripping with water. Under such 

 conditions successful commercial work is not possible. A place where 

 it is possible to maintain a fairly moist condition of the atmosphere, 

 and having such capability for ventilation as will cause at least a grad- 

 ual evaporation, is, by general practice and by the most extensive 

 experimentation, shown co be necessary. With too rapid ventila- 

 tion and the consequent necessity of repeated applications of water 

 to the mushroom bed no mushroom crop will attain the highest per- 

 fection. 



Caves, Cellars and Houses. 



Caves, cellars and abandoned mines, or specially constructed houses, 

 are used for growing mushrooms, because in such places only can the 

 conditions of temperature and moisture be best regulated. Cold is 

 less injurious to mushroom beds than heat. The former renders the 

 bed for a time unproductive; but the latter stimulates the spawn to 

 too rapid growth, which is usually followed by production of un- 

 salable mushrooms, or the eventual death of the spa-mi, supposedly 

 by damping off. 



Mushrooms may often be grown in a very simply constructed shed 

 or unused barn which will provide against any sudden changes of the 

 temperature, and when it is possible to employ artificial heat the sea- 

 son for mushroom production in such structures may be greatly ex- 

 tended. Cellars are very commonly used in producing mushrooms 

 for family use. Natural or artificial caves are of the first importance, 

 however, for commercial work, since the situation of these below the 

 surface will best insure a temperature throughout almost the entire 

 year more or less close to that which is desired. In selecting caves 

 or cellars, one should guard against the possibility of flooding or of 

 too much seepage water during a rainy season. Perhaps the least 

 satisfactory situation among those mentioned is the greenhouse. 

 Under ordinary circumstances it heats too rapidly during daj^s of 

 warm sunshine, and, unless special precautions are taken, it is not to 

 be generally recommended for amateurs. Nevertheless, during the 

 fall and winter it is possible to grow mushrooms under the benches 

 or in any other unused space with but very little outlay of money or 

 labor. Cold frames may be also used to good advantage during the 

 autumn or spring. The natural caves of this country and abandoned 

 coal mines in some sections should be further investigated with re- 

 lation to their adaptability for the commercial production of mush- 

 rooms. A thorough study should also be made of open-air conditions. 



