Texas Gardening: Suggestions sought for sloping beds on east and north sides, 1 by Diffus

Diffus wrote:
I have two beds I would really like to do something with.

The first one faces east. It extends about 15 feet from the house before beginning to slope down to the driveway and a retaining wall that borders the driveway. It gets morning sun, and the amount of sunlight is further limited by two mature red oaks near the house, one at the corner of the driveway, the other at the northeast corner of the house. It's probably 40 feet long and 30 feet deep.

When we moved in, the bed was filled with Asian jasmine. I got ambitious, intending to make it a showpiece, and removed the Asian jasmine. But I can't figure out what to fill the bed with. The biggest obstacle is that mulch washed or blows away, leaving me with a lot of weeding to do.

The second bed is on the front of the house. It was filled with English ivy when we bought the house. The problem with this bed is that, between the shade from the red oak at the corner and the northwest orientation, it stays pretty shady -- until about 3:30 p.m. during the summer, when it gets blasted by late afternoon sun. This bed is probably 30 feet long by 15 feet deep. I have some dwarf yaupon hollies and dwarf nandinas up against the slab.

I've thought about a row of Anthony Waterer spirea across the front of the second bed. They would obscure the bare ground between them and the nandinas and hollies, meaning I wouldn't have to worry about what to fill the space with or have to weed as often.

Any ideas?

A pic of the first bed: