260 MAKING HORTICULTURE PAY 



a given soil a certain active principle essential to 

 their growth, and will no longer thrive in that place 

 until nature, through her own resources, has re- 

 stored the elements essential to their growth. Space 

 will not permit our going over the whole list of 

 those desirable plants, so we shall give cultural 

 instructions for only a few of the most essential, 

 with the understanding that these rules, with slight 

 modifications, will apply to all. As a rule, it is safe 

 to conclude that when any plant ceases to thrive 

 vigorously, a change of soil is an absolute necessity 

 as is also a division of its crowns of tubers. 



PHLOX 



" Perennial phlox is one of the most useful of 

 our hardy plants, not only because of the great 

 variety of color and marking of their flowers, but be- 

 cause of the fact that with proper care and attention 

 they will keep in flower much longer than almost any 

 other of this class of plants. They should be taken 

 up every spring and the plants separated to a single 

 shoot, and not returned to the same place in the 

 border. The distance, however, from where they 

 grow need not be great. When rootbound the 

 phlox will not produce such magnificent trusses of 

 flowers as when occasionally separated. 



*' Phloxes are gross feeders, requiring strong 

 soil, made rich with well-rotted manure, which 

 should be thoroughly incorporated in the soil. 

 In light soils, to get satisfactory results, a suf- 

 ficient mulch of coarse litter to keep the soil 

 moist and cool is essential. The single plants 

 should be set 6 inches apart each way, in clumps or 

 rows in the border, and when the flower buds ap- 

 pear, cut back, say, one-half of the plants, just 



