56 HOTBED AND COLD FRAME 



stand the more severe operation when they are set in'the 

 garden. 



If only a two-frame bed is made the space allotted to 

 each crop can be reduced. 



The double-glass sash are not to be generally recommended 

 for the following reasons: (1) they are too expensive; (2) 

 they are very heavy to handle; (3) they accumulate and 

 retain moisture between the two layers of glass, which 

 causes their rapid decay; and (4) they collect dirt and 

 moisture between the glasses, which decrease the amount of 

 light that can pass through the glass. However, it must 

 not be thought that the double glass does not possess some 

 good points. The advantages of the double-glass sash may 

 be briefly summed up as follows: (1) a growing tempera- 

 ture is reached earlier in the day; (2) the labor of managing 

 the frames is reduced; and (3) the plants are afforded more 

 thorough protection from cold. Although the double-glass 

 sash do possess certain advantages, the disadvantages seem 

 to overshadow the advantages, and they cannot be generally 

 recommended. 



Comjiosting the Manure.- — The usual material for heating 

 the hotbed is horse manure. Sometimes forest leaves, spent 

 hops, and occasionally sheep and poultry manure are used, 

 but the sheep and poultry manure is usually of more value 

 for other purposes. 



The horse manure should consist of about one-third litter. 

 Where the solid excrement is used entirely the fermentation 

 is usually too violent, and consequently of too short a dura- 

 tion. Straw is the best material for the litter, and manure 

 composed of shavings or sawdust should never be used. 



The manure should be composted before it is placed in 

 the pit. The composting should begin about ten days prior 

 to the time the hotbeds are to be made. The manure should 

 first be piled up in compost heaps. A convenient size of 

 the compost pile is 4 or 5 feet wide and about as high, with 

 length enough to fill the frames. After the heating of the 

 compost has started and is well under way, say two or three 

 days after it is piled, the manure must be turned over, 

 thoroughly mixing the outside of the pile with the inside. 



