Drain pipe at brick

Against any retaining wall, a drain pipe is a good idea. All I had left over from an earlier project was a three-foot perforated section and a solid 10-footer. But that's just enough.

Trench grading, filter fabric, drain rock, pipe, then dirt backfill -- in that order. A gradual slope helps. I haven't figured out yet exactly how to take care of the discharge, which should be very light given the tiny planter area.