ALPINES AND AVALL PLANTS. 



179 



should exist apart from the brick face of the wall. And in this way. 

 First arrange a hidden wall of concrete of 15 inches or 18 inches in 

 thickness, well " battered," so as to be ready for any strain placed upon it. 

 Such a provision may always safely terminate a little below the surface level. 



In rendering the brick wall in front of this, good mortar is obviously 

 no longer a necessity, but for its own safety it is better to render the first 

 foot of brickwork in good mortar, carrying the remainder up in soil or 

 soil and mortar joints to the required height. Usually in such a case the 

 interstices between the bricks have contained the only available soil for 

 the plants. "With no further provision for the plants, it is often a matter 

 of some difficulty in getting the plants established, and this can only be 

 ultimately accomplished by keeping the wall constantly moist— in fact, 

 dribbling the bricks day by day with moisture. Some years ago, however, 

 I conceived the idea, when building up this brick face, of placing a thick 

 plank between the front of the concrete and the outer bricks forminfj the 

 face, the plank being dra^^n up as the work proceeded, and the intervening 

 space thus made filled with soil into which the plants could root freely 

 and at their o\\yi. sweet ^\\\\. 



Advantages of this Space. 



I do not think it will be necessary for me to enlarge upon the 

 advantages of- some such arrangement, and the soil being of a uniform 

 nature in respect to dryness or wetness is in the main an agreeable one 

 for plants to root into. 



Raking Back. 



There is, however, still one thing more that should be done in the case 

 of the brick wall arrangement, and it is this : in building the brickwork, 

 take care that the work be set back and not rendered to one plain facing 

 line. This setting back is known as ro.king back" to the brick-setter, 

 and even though it be but ^ inch in each course of bricks, the 

 ledges thus formed create excellent receivers and retainers of moisture 

 for the plants either in times of wet or of watering, the plants receiving 

 even greater benefits where the bricks are gradually sloped to the back, 

 thus conducting the moisture to the roots of the plants naturally and most 

 effectually also. 



Walls of more Oknamental Character. 



5. Then I would mention those walls intended more for ornament 

 than use. Such as these, of course, can be arranged at will, but if plant- 

 growing be thought of I would suggest the hollow-centred wall, with 

 pockets in its summit and holes or side-pockets in the upper portions. 

 In such a wall with the interior charged with soil, many of the more showy 

 plants may be grown in a highly satisfactory manner. 



Old Walls. 



All these walls are capable of growing plants provided a little intelli- 

 gent care and after-attention be thrown into the work. And provided 

 this very essential part be not neglected it is not difficult to get plants 

 established. 



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