I live in zone 7 (Georgia). There is a 35-45 degree slope away from a picket
fence on my neighbor's property. Mowing is impossible up to the fence. The
fence is about 20 or 25 feet long.

I want to dig up the area for 4 or 5 feet from the fence and plant something
there that would look nice against the backdrop of the fence. It needs to be
easy to tend and needs to stay in the outlined area. Mulch must not wash
away when rainwater runs off my neighbors property.

Any suggestions?