The difficulties in the way of open air culture are not merely those of 

 maintaining a more or less uniform temperature, but also of main- 

 taining practically Constant conditions of moisture. For these 

 reasons it is necessary to mulch the beds heavily with clean straw. 

 In some instances a light mulch of straw is permitted to remain 

 even during the period of production, for a rapid drying out of the 

 surface would be hazardous or fatal. It is better, perhaps, to put 

 the beds under some form of protection, such as an improvised cold 

 frame. 



In r,egions where the climatic changes are marked, open-air culture 

 is probably not to be recommended during any season for commer- 

 cial purposes. It is probable that there are some areas in the United 

 States in which open-air culture might be practised with profit. 

 It has seemed that certain sections of California might be favorable 

 for this phase of the work. In the interest of experiments along 

 this line the writer has made a special attempt to acquaint himself 

 with the conditions in that section of the country. This has seemed 

 particularly desirable, inasmush as fresh mushrooms could not be 

 shipped to the far West from sections in which they are at present 

 grown in quantity. From the information obtained it is thought 

 •that successful open air mushroom growing might be anticipated 

 in those sections where the average temperature is between 48 deg. 

 and 55 deg. F., provided there are relatively few days when the tem- 

 perature falls as low as 32 deg. F. At the same- time, open air cul- 

 ture cannot be recommended for those sections in which dry winds 

 are prevalent. As a rule, during the wet or winter season the rain- 

 fall is so light that heavy mulching would probably suffice to prevent 

 injury from excessive wetting. Nevertheless, it seemS: apparent 

 that even in regions most favorable for open-air culture some inex- 

 pensive partial protection against the changes of temperature due 

 to direct sunlight, or against heavy rainfall, would be desirable. 



LAWJfS AJfD PASTURES — Lawns and pastures may be inocu- 

 lated by breaking a piece of spawn in four pieces and inserting the 

 same under the sod about two feet apart. Plant in the summer 

 and if the season is not too wet rpushrooms will appear in the fall. 

 Ayoid depressions where water would remain stagnant, as an excess 

 of moisture destroys the spawn. Since weather conditions render 

 open air culture rather uncertain, tha use of fresh high grade spawn 

 might be considered expensive. It- is often possible, in such case,, 

 to obtain from dealers at a much reduced price, spawn which has 

 been kept in stock for some time and cannot therefore be sold as 

 strictly fresh. The grower, thus incurring no expense in the prepara- 

 tion of beds, runs no chance beyond the small outlay for the spawn. 



13. Mushroom Enemies 



Under suitable conditions and with the exercise of constant 

 vigilance as to general cleanliness the mushroom bed will seldom fail 

 as a result of diseases or insect depredations. Nevertheless, every 



