This shed wall, in my concrete back yard, is south facing and a great sun trap. I plan to build a raised bed against this wall using a low concrete wall in front. Is there an optimum height and width for such a bed? I hope to grow shrubs, fruit and veg in it.
If there is soil there already, you should first ask yourself what does the raised bed add? These are not essential for the purposes you suggest and teh bed might simply dry out in a warm summer and require endless watering.