186 GREEN-HOUSE. [January 



GREEN-HOUSE. 



JANUARY. 



This compartment requires particular attention, in order 

 to preserve tlie plants in good health, and carry them through 

 this precarious season of the year. A little air must be ad- 

 mitted at all convenient times. An hour or two at mid-day 

 will be of the utmost importance in drying up damp and 

 clearing off stagnated air, which is a harbor for every corrup- 

 tion. The top sashes being let down or turned a few inches, 

 in mild days (that is, when there are not high and cutting 

 winds), from ten or eleven o'clock to two or three, according 

 to the intensity of the frost, will renovate the interior air of 

 the house and harden the plants. When the weather will 

 permit, let the front sashes be opened about one inch or 

 more. An assiduous, experienced hand will never omit an 

 opportunity. 



With regard to fire heat, the temperature must be regu- 

 lated to suit the nature of the plants in a general sense ; so 

 let the mercury, or spirits of wine, of Fahrenheit's thermo- 

 meter, be from 35° to 50°; if it begins to fall, give a little 

 fire heat. No doubt we have seen the thermometer much 

 lower in the green-house than the above, even as low as 24°, 

 without any immediate injury; but it v/as in an extensive 

 collection, where the most hardy of the plants were selected 

 into one house. Many boast how little fire they give their 

 green-house, and how cold it is kept, not observing the 

 miserable state of their plants — inexperience causing them 

 to think that the least fire heat will make them grow, and 

 would rather look on naked stems than healthy plants. The 

 above temperature will not, in exotics, cause premature vege- 

 tation, but will cause the plants to retain the foliage requisite 

 to vegetative nature. K high temperature is not necessary 

 for the generality of green-house plants; on the contrary, it 

 might very much injure them. 



