HOTBEDS AND COLD FRAMES 95 



ance should be made for this fact when filling. After 

 the manure has been placed in the pit to the proper 

 depth it should be covered with four to six inches 

 of good garden soil. The heat runs very high for 

 a few days, after which it begins to drop. 



Neither seed nor plants should be placed in the 

 bed before the temperature falls to 90° Fahr., or 

 less. The frame is usually banked with manure 

 around the outside in order to afford additional 

 protection. When the hotbeds are to be run during 

 the winter time, or in the more northern portion of 

 the country, it is common practice to dig the pit 

 about a foot wider than the frame in all directions. 

 The portable frames are then placed on the top of 

 the manure and the frame banked around the out- 

 side with the same material. This plan requires 

 considerable manure, but furnishes more heat, which 

 lasts for a longer period. 



The manure from the spent hotbeds is used for 

 composting and fertilizing purposes where large 

 amounts of nitrogen are not essential or where it 

 may be applied in some other form. 



Hotbeds are frequently constructed in such a way 

 that they may be heated by a system of flues lead- 

 ing from a furnace burning coal, wood or any other 

 convenient fuel. The flue-heated hotbed has the 

 advantage of giving the operator more perfect con- 

 trol over the heat, and is not troubled with tem- 

 perature falling below the safety point before the 

 plants are sufficiently mature or the season safely 

 advanced. In connection with greenhouses, hot- 

 beds are frequently constructed in such a way that 

 they may be heated by steam or hot water from the 

 general greenhouse heating system. 



Cold frames may be described as hotbeds without 



