ROCK GARDENS 265 



never attempt to naturalize it, and never at- 

 tempt to bring it into the ensemble. Neither 

 can be done nor even attempted without disas- 

 ter all the way around. 



In planting either a rock garden, a wall gar- 

 den, or a rockery always bear in mind that ex- 

 posure is of the greatest importance. Never put 

 plants on a bank exposed to the south if they 

 belong to the list of those succeeding under 

 northern exposure. This often accounts for a 

 specimen remaining alive only as long as it takes 

 to plant it. For though it may seem only a 

 small point it is vital — as will appear readily 

 enough when one recalls how long a patch of 

 snow will last on the north side of a hedge or a 

 fence or mass of shrubs, as compared to one on 

 the south side. The continuous direct rays of 

 the sun are as fatal to those plants that have 

 been evolved in shade or part shade as shade 

 and its accompanying chill are to the sun-loving 

 plants; and this is not altogether on account of 

 the heat involved but because of all the accom- 

 panying phenomena. 



PLANTS FOR ROCK AND WALL GARDENS 



Northern Exposure or in Shade 

 Prostrate and Carpet-like 

 Starry grasswort Cerastium arvense White 



Woolly grasawort Cerastium tomentosum " 



Bugle weed Ajuga reptans Blue 



