THE GROWING OF THE ORNAMENTAL PLANTS 233 



sheared evergreen. Sometimes the rocks are natural to the 

 place and cannot well be removed; in this case the planning and 

 planting should be such as to make them part of the picture. 



The real rock-garden, however, is a place in which to grow 

 plants. The rocks are secondary. The rocks should not ap- 

 pear to be placed for display. If one is making a collection of 

 rocks, he is pursuing geology rather than gardening. 



Yet many of the so-called rock-gardens are mere heaps of 

 stones, placed where it seems to be convenient to pile stones 

 rather than where the stones may improve conditions for the 

 growing of plants. 



The plants that will naturally grow in rock pockets are 

 those requiring a continuous supply of root moisture and a cool 

 atmosphere. To place a rockery on a sand bank in the burning 

 sun is therefore entirely out of character. 



Rock-garden plants are those of cool woods, of bogs, and par- 

 ticularly of high mountains and alpine regions. It is generally 

 understood that a rock-garden is an alpine-garden, although 

 this is not necessarily so. 



In this country alpine-gardening is little known, largely be- 

 cause of our hot dry summers and falls. But if one has a rather 

 cool exposure and an unfailing water supply, he may succeed 

 fairly well with many of the alpines, or at least with the semi- 

 alpines. Most of the alpines are low and often tufted plants, 

 and bloom in a spring temperature. In our long hot seasons, 

 the alpine-garden may be expected to be dormant during much 

 of the summer, unless other rock-loving plants are colonized 

 in it. Alpine plants are of many kinds. They are specially to 

 be found in the genera arenaria, silene, diapensia, primula, 

 saxifraga, arabis, aubrietia, veronica, campanula, gentiana. 

 They comprise a good number of ferns and many little heaths. 



A good rock-garden of any kind does not have the stones piled 

 merely on the surface; they are sunken well into the ground 

 and are so placed that there are deep chambers or channels that 



