Keeping Plants Hale and Hearty 73 



Temperature, of course, is the factor which 

 will require most constant attention, as the con- 

 ditions affecting it change not only from day to 

 day, but even from hour 

 to hour. Here, again, as 

 with most other things 

 connected with the grow- 

 ing of plants, you can ap- 

 ply common sense. You 

 know that the thing 

 above all others to be 

 avoided in taking care of 

 the baby is a sudden 

 change in temperature; 

 the same thing applies to 

 your plants. It is not 

 the low or high tempera- 

 ture itself, but the shock 

 of a sudden change which usually does the dam- 

 age. That is why it is so essential to have a 

 good, sturdy, well-constructed house which is 

 tight, and in which the heating system is not 

 only adequate in size, but made for greenhouse 

 heating. Further reference to this subject is 

 found in Chapter XV. 



Temperature is controlled by the heating and 

 ventilating systems, both of which are simple 

 enough. The big difference between greenhouse 



A turn or two of the little 

 wheel, and your glass garden 

 is flooded with fresh aii — as 

 much or as little as may be 

 required. 



