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 season for mushroom production in such struc- 

 tures may be greatly extended. 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 cir- 

 cumstances it heats up too readily during the days 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 also be 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 investi- 

 gated with relation to their adaptability for the commercial pro- 

 duction of mushrooms. A thorough study should also be made 

 of open air conditions. 



boileu 



pe/fSPecT/i/e or HEATiNq p/pcs. 



In the construction of special mushroom houses any one of a 

 variety of plans may be followed, and the selection of the style 

 will depend, of course, upon its cheapness and efficiency in the 

 particular locality. 



6. Preparation of the Compost 



It is not to be understood that there is one and only one method 

 of preparing compost for mushroom growing. Nor is it always 



