278 



POPULAR GARDEN BOTANY. 



it is desirable to bring forward still more rapidly, may after 

 this increased heat be removed to the hothouse, to enjoy 

 the still warmer atmosphere established there. "No plants 

 should be suddenly placed in a great heat, as from the outer 

 air to a warm greenhouse, or from a cool greenhouse to the 

 stove; it is advisable to begin with a cool atmosphere, and 

 gradually increase it ; they will at last bear a temperature of 

 sixty or sixty-five degrees, and then produce their flowers 

 in abundance. Air must be freely admitted into the green- 

 house, but a draught must be avoided. During frost, severe 

 winds, or heavy fogs, the windows should not be opened ; 

 but at all other times, when the sun shines, or when the 

 outer atmosphere is not lower than forty degrees, the sashes 

 should be open, and the time of opening in the morning 

 and closing at night be regulated by the season and weather. 



The supply of water must also be regulated by the season : 

 in winter, only sufficient should be given to keep the soil 

 from becoming quite dry ; in summer more frequent water- 

 ing is required, as the evaporation is greater, and plants 

 take up more when in a growing state. It is a good plan 

 to water thoroughly at once, so that every part of the soil be 

 wetted, but not to give more till it is becoming dry : plants 

 are killed as often by too much as too little water, 



