Not sure why the picture is upside down...

Anyway, this is the south side of my house, gets full sun and I'm in Washington, zone 7/8 depending on who you ask. Looking for plant suggestions to hide the foundation pictured.

Challenges: 1. drain pipe roughly 1-2 feet down (depending on how far along the house you are) = trying to avoid plants with woody/aggressive roots. 2. Abysmal soil. Lots of gravel and spiders (eek.) Though a good amount of worms too so it can't be too terrible. 3. Currently, a lovely patch of horsetail is rooted there (temporarily disabled when I tore out the grass strip as seen in the photo.) I've accepted the fact that it won't die in the near future, but I'm thinking I need to avoid dense/thorny plants that would preclude my once weekly weeding battle against the stuff.

Oh, and potted are a dwarf Washington naval Orange, strawberry towers, and a Meyer lemon. Strawberries went container route since my dog likes to murder plants, but I'm willing to put up a garden fence depending on what else I plant there.

I'm considering day lilies or iris...something fairly tough but I'm having trouble visualizing how much those would hide. Thanks in advance for your help!!!