How high is the wall and how far down do you want the shrub to hang?

How high is the wall and how far down do you want the shrub to hang?

Creeping or spreading yews (Taxus species) are perhaps the most shade tolerant of the coniferous evergreens and will serve a purpose similar to that of junipers for full sun. But they are not the most effective at hanging or draping over a wall. You might want to consider a shade tolerant groundcover for that type of activity......vinca minor would work well, providing it will be located well away form any natural areas.

I was even thinking climbing hydrangea. They can be trained to hang down, not evergreen, but very interesting bark.

The wall is about 4' high.

I'd do a mix of perennials, you can do Gaultheria procumbens (wintergreen! chew on the berries/leaves, evergreen to semi-evergreen) and the sprawling Phlox divaricata which will flop over if planted on the edge. Phlox divaricata 'May Breeze' is a beautiful off-white/dove grey/baby blue (really strange color) and there are others that come in a bevy of pretty purples too.

Microbiota decussata or Russian cyprus seems to take shade.

I'll think of others.

ooh, those are good ideas. I forgot about phlox!