FORCING AND RETARDING PLANTS 163 



this, since the food necessary for their growth and even the 

 blossoms themselves are formed in the underground parts dur- 

 ing the preceding season. If given sufficient water they are 

 able to develop their flowers with very little light, since blos- 

 soming with them is largely a mere expansion of parts already 

 formed. They may be grown in soil or water, but in either 

 case they are usually set aside in some cool dark place, after 

 planting, to form roots before being placed in the light. The 

 most popular subjects for growing in this way are the paper- 

 white narcissus and the Chinese sacred lily, a closely related 

 species, but tulips, crocuses, hyacinths, and other bulbous plants 

 are also grown. After flowering, the plants are usually thrown 

 away, since they cannot be satisfactorily forced a second time. 



PRACTICAL EXERCISES 



1. At the proper time make a hotbed or cold frame in the school 

 garden and plant in it seeds of long-season plants that may be trans- 

 planted to the open ground later. Make a sowing of lettuce, beets, or 

 onions for transplanting. 



2. Dig up spring flowering plants before they start into growth and 

 place in cold storage, to be brought out and flowered when those in the 

 fields have gone. 



3. Try forcing sea kale, asparagus, or rhubarb. 



4. Make a single forcing hill for growing some plant from seeds, 

 such as melon. 



5. Try forcing some wild plant at the beginning of winter. Etherize 

 another plant of the same kind and compare results. 



References 



Bailey, "The Forcing Book." 

 Bailey, "Manual of Gardening." 



