All Kinds of Greenhouses 285 



ing sunshine into flowers or luscious fruits, gen- 

 erally right against the calendar. Yet it is timely 

 to remember right here and now that this is not 

 exactly what happens in a greenhouse. As a 

 matter of fact, gardening under glass is not 

 simply protected-from-the-weather gardening, 

 wherein the work is carried on with the same 

 materials as are used out of doors; but rather it 

 is gardening with very special materials in most 

 cases, as well as under highly artificial conditions. 

 In the greenhouse three of the four factors of 

 garden work are controlled, but the fourth is 

 quite beyond control. Temperature, soil, and 

 moisture are adjusted as delicately as necessity 

 demands; but light still remains outside the reach 

 of all our cunning — and what is more, light is 

 diminished always, however cleverly we may 

 build, quite apart from the fact that normally 

 light diminishes greatly in winter, just when we 

 expect the greenhouse to be most active! So 

 that while we control the three and increase these 

 however we will, we diminish the fourth in spite 

 of everything; and create, therefore, something 

 quite different from any outdoor conditions. 



A New World Opens up 



Realize, therefore, that you do not need to con- 

 fine yourself to the plants of our outdoor gardens 



