284 NATURE-STUDY 



felt of fine roots. Before they turn dark the plant should 

 be transferred to a pot an inch larger. Tip the pot, hold 

 the hand over the earth, and slightly tap the edge of the pot 

 against a table to loosen it. Put into a new pot as directed 

 above, removing some of the old soil from the top and margin. 



Watering: Do not. water except when the plant needs 

 it. Then give a good soaking. But do not allow the soil to 

 remain soggy all the time, for that injures most plants. The 

 roots need air as well as water.. The soil should be moist, 

 but not soaking. 



Turn the Plants to make them grow symmetrically, 

 else they will develop mainly on the side toward the light. 

 Do not crowd the plants in a window so that they cut off 

 each other's hght. 



Window-boxes: These should be not less than eight 

 inches deep, about the same in width, and as long as the 

 window permits. Put drain holes in the bottom. A metal 

 tray to catch the moisture would protect the sill. Oilcloth, 

 however, will do as well, if the box is raised slightly on strips 

 of wood placed under it to allow the moisture to dry. The 

 boxes should be well made. They may be made of galvan- 

 ized iron, or more cheaply of wood. They should be painted 

 to prevent warping as well as for looks. Use the potting soil 

 given above. 



These window-boxes may be used in a variety of ways. 

 To a certain extent the principles of gardening can be taught 

 with them. Germination studies, soil studies, starting of 

 plants for the outdoor garden, experiments on plant be- 

 havior, planting of tree seeds and pits, the propagation of 

 plants by slips, layering, and grafting — all these things can 

 be demonstrated in the httle window gardens. 



