I'm looking for ideas for a planted area at a commercial building. The area is outside, so it's subject to freezing, and is basically a raised bed. However, it sits above the basement, so it is lined with a pond liner and has a couple inches of stone at the bottom for drainage (above the liner). It is part of a covered entryway, so it gets no direct sunlight. Here are some specs:

• Heavy shade

• Soil depth = 2-3" in most places; 7" in others

• Roughly 75 square feet

• Zone 6b or 7a

I'm looking for something that would stay green year-round that wouldn't require a lot of water once established.

I talked to a local nursery, and they only came up with Creeping Jenny. I'm fine with that, if that's the only option, but I was hoping for some variety.

Where the soil is the deepest (7"), there is a glass display window behind that, so I wouldn't want anything taller than 12" there. Beside the window there is a solid wall, so something could be trellised there.

I'd prefer something that flowers, but it's not necessary. The top priority is green throughout winter so I don't have a dead patch at the front of the building.

Any suggestions?