226 



PRACTICAL LANDSCAPE GARDENING 



PrTAIL R?l? PEY F?fTW/1lA)Q WALL TO W PLA/ljep 



Fig. 174. — Dry stone wall with pockets for planting. Note system for watering. 



as would be necessary if the line was directly connected vdth the 

 water supply system. Where the rock garden is close enough to 

 the house, water may be applied directly by hose, but the irrigation 

 method is to be preferred. 



An interesting use of rock and Alpine plants is in the planting of 

 dry walls (Figs. 172 and 173) and particular!}^ when such walls are 

 built as retaining waUs in the flower garden. A great variety of 

 plants may be had for such a purpose and the list greatly enlarged 

 if a water supply is near by to help out in very dry periods. 



When it is purposed to plant the interstices in dry walls, the 

 walls should have a batter (Fig. 174) of three inches to the foot, or 

 one foot in a wall four feet high. The stones should be set at a 

 right angle to the inchned line. The pockets left for plants should 

 continue directly or indirectly through the wall so that the soil ■nill 

 be in direct contact with that at the back of the wall. These soil 

 pockets should be filled as the wall progresses and the soil held in 

 place by tough pieces of sod until ready for planting. 



For wall gardens it is advisable to install a sub-irrigation 

 system (Fig. 174) to supply abundant moisture to the wall 



