190 GREEN-HOUSE. {January 



GREEN-HOUSE. 



JANUARY. 



This compartment requires particular attention, in order 

 to preserve the 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 harbour 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 regulated 

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

 mercury, or spirits of wine, of Fahrenheit's thermometer, 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 was 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 vegetation, but will cause tho 

 plants to retain the foliage requisite to vegetative nature. A 

 high temperature is not necessary for the generality of green- 

 house plants; on the contrary, it might very much injure 

 them 



