PLANNING THE HOME GARDEN 127 



The pupils should be encouraged to do all the work of 

 preparing the land as well as planting the seed and caring 

 for the plants. The preparation of the soil can be converted 

 into a lesson in soil physics, the teacher explaining the nature 

 of the soil as a source of plant food, as a mechanical support 

 to the plant, and as a storehouse and conveyor of water 

 and air. The influence of tillage on the liberation of 

 plant food and water content, the importance of hoeing or 

 cultivating to eliminate competition by the destruction of 

 weeds and to conserve moisture by the maintenance of a 

 soil mulch, and the necessity of thinning the plants in the 

 row in order to reduce competition and increase the feeding 

 area of the individual plant, should be clearly presented. 



The influence of pruning on tomatoes to lessen competi- 

 tion among the branches and increase the food supply to the 

 fruits retained should be brought out. The plants them- 

 selves offer material to use as a basis for discussing their life 

 processes, including germination, growth, the functions of 

 leaves, stems, roots, and flowers, and, finally, the storing 

 of material in the finished product. 



