CULTIVATION OF ALPINE PLANTS 49 



grow upon it. Thus, even in the Swiss Alps, there 

 are some plants that are purely saxatile growing in 

 very narrow and deep fissures or chinks between the 

 rocks, needing hardly any soil for their nourishment 

 and getting all the food and protection they require 

 from the rocks which surround their roots. Plants 

 of this kind are apt to be very deep-rooting, and, 

 when once they have thrust their roots down among 

 the rocks deeply embedded in the soil, they are usually 

 safe against any amount of drought and heat in the 

 summer or moisture and cold in the winter. The 

 more difficult among them need scarcely any soil 

 at all, merely a little grit and rubble to fill up the 

 spaces between the rocks. They will usually thrive 

 on a steep, sloping bank; and there is no need to ar- 

 range the rocks where they grow so as to catch and 

 hold the water on the surface of the soil, as they get 

 all the moisture they need from the rocks about their 

 deeper roots. Most of them like all the sun they can 

 get, and should, therefore, be grown on rock-work 

 facing to the south. Many plants of this kind which 

 can be successfully grown in English rock gardens 

 come from mountains in Asia Minor and other hot 

 countries, so that they sometimes suffer from very 

 sharp frosts, especially if accompanied by cutting 

 winds. They should therefore be grown in sheltered 

 places, and in very hard winters should be protected 

 with a mat or cut heather. 1 Among plants of this 

 deep-rooting purely saxatile character may be men- 

 tor "cut heather" Americans may read "pine boughs." L. Y. K. 



