DETACHED GREENHOUSES, ETC. 183 



indicate one hundred degrees or more ; but this is yet 

 too hot as bottom heat for the growth of seeds or plants, 

 and a few days of delay must be allowed until the ther- 

 mometer indicates a falling of eight or ten degrees, when 

 four or five inches of soil may be placed upon the manure, 

 and the seeds sown or plants set out in the hot-bed. Am- 

 ateurs are apt to be impatient in the matter of hot-beds, 

 and often lose their first crop by sowing or planting be- 

 fore the first violent heat has subsided. Another very 

 common mistake is in beginning too early in the season. 

 In the latitude of New York nothing is gained by begin- 

 ning before the first week in March, and the result will 

 be very nearly as good if not begun until a month later. 



There are two or three important matters to bear in 

 mind in the use of hot-beds. It is indispensable for 

 safety to cover the glass at night with shutters or mats 

 until all danger of frost is over ; for it must be remem- 

 bered that the contents of a hot-bed are always tender, 

 from being forced so rapidly by the heat below, and that 

 the slightest frost will kill them. Again, there is danger 

 of overheating in the daytime by a neglect to ventilate 

 when the sun is shining. As a general rule, it will be 

 safe in all the average days of March, April, and May, to 

 have the sash of the hot-bed tilted up from an inch to 

 three inches at the back from 9 A.M. to 4 P.M. Much 

 will, of course, depend upon the activity of the heating 

 material in the hot-bed, the warmth of the weather, and 

 the character of the plants in the bed, so that we can 

 only give a loose general rule. Numbers of inexperienced 

 amateur cultivators often lose the entire contents of 

 their hot-beds by having omitted to ventilate them, and 

 on their return home from business at night find all the 

 plants scorched up ; or the danger of the other extreme 

 is, that the plants are frozen through neglect to cover 

 them at night. A hot-bed requires a certain amount of 

 attention, which must be given at the right time, or no 



