THE WINDOW GARDEN 3 



If plants are to develop symmetrically, they must 

 be turned frequently, but it is usually best to let the 

 leaves occupy the same position with reference to the 

 light from day to day. Plants will not thrive if they 

 are changed so that strong sunlight falls on the under- 

 side of the leaves. 



Fresh air containing the required amount of moisture 

 is as important for plants as for children ; neither can be 

 kept in health without it. But drafts must be avoided ; 

 no cultivated plant can be submitted to a draft for any 

 length of time without injury to its foliage or blooms. 

 Special care must be taken in the spring, when the 

 weather may change completely in the space of an hour. 



In most schoolrooms the dryness of the air, caused by 

 artificial heat, must be counteracted by keeping the 

 water pan in the furnace air chamber well filled. In 

 the case of steam-heated rooms the normal amount oi 

 moisture may be obtained by allowing steam from the 

 radiator valves to escape at intervals. 



Dry heat absorbs the moisture from the foliage, and 

 the fine dust that is always afloat in the excessively dry 

 schoolroom atmosphere fills the stomata (the openings on 

 the underside of the leaves, through which they obtain 

 air) and causes the plants to become sickly and subject 

 to the attack of insects. 



The ordinary temperature of from sixty-eight to 

 seventy degrees, which may go as low as fifty overnight, 

 is suitable for nearly all house plants. Large school 

 buildings should never be permitted to have a lower 



