66 ROGK GARDENING FOR AMATEURS 



its composition ensures comparative dryness to the 

 roots of the plants in winter, and assures against drought 

 in summer. This apparently paradoxical statement is 

 easily explained. It is obvious that the heavy rains of 

 winter will pass through a mass of broken stone more 

 readily than through a similar body of soil, but how it 

 manages to remain moist in summer is, perhaps, not so 

 apparent. Every gardener has probably often noticed 

 on removing a large stone that the soil beneath it is 

 moist, while the surrounding soil, not similarly covered, 

 is dry. The explanation, no doubt, is that the stone 

 prevents loss of moisture by evaporation. The broken 

 stone of the moraine acts similarly, if the work is properly 

 carried out. Further, the plants are not so liable to 

 damp off at the ground level, and they become thoroughly 

 " ripened " in summer by the heat from the stone. 

 The latter is a matter of some importance. It is sur- 

 prising to feel how hot the stone becomes on a sunny 

 day, and it retains the heat for a considerable time. 



Natural moraines are invariably kept moist during 

 spring and summer by the constant passage through 

 the stones of mountain streams, thus ensuring adequate 

 sustenance for the roots of plants growing in them. In 

 fact, it has been declared that a moraine is not rightly 

 fashioned unless it is kept moist by a constant supply 

 of underground water. However, it has been found 

 that, so far as the moraine in gardens is concerned, a 

 supply of water through the stones is not essential. 

 It depends largely upon climatic conditions. In very 



