I cope with these conditions by looking at plants that require partial shade or plants that are listed as full sun/partial shade. To cope with tree roots, I'd look for plants that don't require a lot of moisture (no astilbes, ferns that can take dry conditions, and so on). As a matter of fact, I might fill in the area with autumn fern - fairly formal, evergreen, can take some sun, grows well under trees. And they're pretty.

If you decide on ferns, all you need to do for maintenance is make sure each fern gets a shovel full of compost spread around it each fall or spring. And make sure each planting hole gets three to five shovels full of compost worked in when you plant the ferns. Keep them watered and you're good to go. Can you tell I've already decided on autumn ferns for you?

Autumn ferns sound perfect for that spot. Thanks very much.

Azaleas, rhodos and camellia japonicas should be fine. Just about any shade plant would be ok as long as you provide ample moisture.