102 The American Flower Garden 



gradually increasing as the cutting proceeds and then diminishing 

 again toward the exit, will vary according to the amount of soil 

 thrown up on the banks. After rocks have been added to the 

 slopes, an excavation of only three feet may make a total depth of 

 six. Of course, the cutting is not done in a straight line, but in a 

 gently curving one, in the hope of creating an impression of natural- 

 ness as well as affording a variety of exposures to plants of varying 

 needs. The marvel is that such an absolute fake as an under- 

 ground rock garden can ever be convincing. Needless to say, it 

 takes an artistic genius to make it so. Yet there is a rockery of this 

 purely artificial type at Kew Gardens, London, which is a joy to all 

 beholders; another good one, cut into a bank by the same under- 

 ground method and executed by a former Kew man, 

 thrives on the grounds of Smith College, Massachusetts. Many 

 others are partly natural and more or less cut out underground; 

 but never in this dry land of ours was a successful rock garden 

 made on a sunny southern slope, where the rain runs rapidly away 

 or evaporates, unless a cascading brook or water introduced by 

 pipes among the rocks keeps up a never failing supply of moisture. 

 So much of the success of a rock garden, cultural as well as 

 artistic, depends upon the placing of the stones, that one needs to 

 proceed almost as cautiously as a Japanese extremist. Of course, 

 the fundamental idea of a rock garden is to suggest a natural, rocky 

 slope such as is seen on the mountain sides where alpine plants have 

 their origin, but with its excellences condensed into a small area, 

 its beauties emphasised by art and the number of its desirable 

 plants greatly increased. Such a scene, however, will be of short- 

 lived beauty unless the best possible situation and soil for every 

 plant that one attempts to grow have been given it. It is better to 

 devote one's first thought to providing a healthful home for the 



