The south and west facing wall make the perfect site for growing wall shrubs. Plants growing on such walls bask in the heat of warm sunny days and usually respond by producing a greater profusion of flowers. Such sheltered sites  make an ideal spot for a patio or sitting area and when plants with fragrant flowers are planted a most pleasing ambience  for out entertaining is created.

 In cold districts a warm wall can make a real difference to the survival of marginally hardy plants. Such walls act like a storage heater, they absorb the heat during the day and release the heat during the night and early morning thus giving several degrees of frost protection. Since these walls do not receive early morning sun, plants warm up slowly after frost  avoiding damage that the rapid thawing can cause to frozen leaves and buds

 Plants will not only have to contend with drought in such a sheltered situation but also with pests and diseases. To reduce these problems, improve the soil, plant 18" away from the wall, mulch to reduce surface evaporation (gravel or pebbles would be most suitable) and spray before pest and diseases can become a big problem.