CHILDREN'S GARDENS 



long period for the development of leaves, stems 

 and wood, and the quantity of flowers and fruit 

 depends upon the efficiency of the work done by 

 the vegetative parts. Potash, phosphoric acid 

 and lime contribute to the growth and hardening 

 of the wood and the maturing of the fruit. Suffi- 

 cient nitrogen must be supplied to preserve vig- 

 orous, vegetative activity of trees and shrubs. 

 Potash is most important to flowers and herba- 

 ceous plants, and in the form of ground bone 

 furnishes phosphoric acid and nitrogen. Com- 

 mercial fertilizers are concentrated forms of 

 nitrogen, phosphoric acid and potash. Lime 

 improves the physical condition of the soil, over- 

 comes acidity and aids the plant in setting free 

 unavailable plant-food. 



Some plants are cultivated for their great 

 development of leaves, as lettuce, spinach, Brus- 

 sels sprouts, cabbage, celery and rhubarb ; others, 

 for their storehouses of nourishment, to be used 

 for developing flowers and maturing seeds, as 

 radishes, beets, turnips, parsnips and potatoes; 

 others again are raised for their fruit or seeds, 

 as cucumbers, squashes, pumpkins, melons, to- 

 matoes, beans, peas and corn. Plants with large 

 leaves, as cabbage, cauliflower, Brussels sprouts 

 and lettuce, make a great demand upon the soil. 

 They require nitrogen and phosphoric acid, and 

 with light soils some potash. Care should be 



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