156 GARDEN PLANNING 



One great charm of the rock garden is its 

 variety, and that can best be maintained by- 

 providing all the conditions of aspect and ex- 

 posure demanded by the various plants avail- 

 able for our purpose. 



Materials — Perhaps the best material for 

 the purpose is sandstone, but in most cases 

 the gardener has to be content with what is 

 most easily obtainable in his district. A 

 hard, close-grained sandstone, granitic rock, or 

 tuffa, limestone, and conglomerate will do. 

 Soft stones which crumble away under weather 

 influence are obviously unsuitable. 



If natural stone is unprocurable, or its cost 

 prohibitive, then the gardener must make 

 shift with brickyard waste, but he should select 

 that which is porous. 



Clinkers, vitrified brick fragments, dressed 

 stone blocks, portions of decayed statuary, 

 lumps of alabaster, minerals, and sea-shells 

 should never be seen in the alpine garden. 

 Tree stumps also should be avoided, as they 

 harbour fungi to the detriment of the plants. 



The stone pieces should not be too small nor 

 too uniform in size. Good bold pieces up to 

 the largest size the gardener can conveniently 



