Planting 161 



and plants were set as soon as the ridges were com- 

 pleted (Fig. XLIII). 



In December, 1920, after the ground had frozen 

 hard, the plants were given a light covering of straw 

 (Fig. XLIV). 



Early in 1921, at the first indication of growth, all 

 the covering was removed. In May the plants 

 except a few whose rhizomes were very small when 

 planted (second row from right, below), and except 

 the germanicse (first row) whose rudimentary flower- 

 stems probably had been injured by a severe late 

 frost bloomed as abundantly as Irises transplanted 

 early the previous season ordinarily do (Fig. XLV). 



FIG. XLV. THE IRISES IN FIG. XLIII, IN MAY, 1921 



Notwithstanding the excessive heat and unusual 

 drought the ensuing summer, every plant grew vig- 

 orously and not one was affected by any disease or 

 trouble of any kind (Fig. XLVI). 



The Iris is as indifferent to atmosphere as to soil. 

 While of course it thrives best in a reasonably pure 

 atmosphere, and is less sightly with soiled foliage, 

 it does remarkably well in an atmosphere frequently 

 and to a considerable extent charged with dust, smoke 

 or soot. 



