The Time for Planting 



147 



Purdue Agric. Expt. Sta. 



FIG. 83. A group of home-made plant forcers. One is placed over each plant 

 or hill of plants. It has a frame of wood and a glass top. Each plant forcer is 

 thus a miniature greenhouse or cold frame that can be removed as soon as warm 

 weather arrives. In the illustration the forcers are being used on rhubarb. 



ing dates for the vegetables he wishes to grow in his 

 own garden. 



TEMPERATURE REQUIREMENTS AND GROWING PERIODS 

 OF DIFFERENT GARDEN CROPS 



Garden crops may be divided into cool-season and 

 warm-season crops. The seeds of cool-season crops ger- 

 minate in the cool soil of early spring, and their seedlings 

 are not much if at all injured by moderate frosts. 

 The growing plants of this class thrive during cool 

 weather, and most of them mature during the cool 

 weather of either spring or fall. In the more south- 

 ern states many of these crops are " fall and winter " 

 crops, growing and maturing from September to 

 May. 



