I have lilies planted in that situation, but I filled in around it lower growing plants that shade the root a bit. I have a new bed that I am still working on though & right now the lilies are in full sun all day, doing fine so far & I hope by the time summer is here & really hot some of the other plants will protect them a bit.

Yup, that's what I plan on doing, just haven't figured out what else I want there yet to sit lower.

Lilies do prefer sun, but also like the lower portion of the plant to be shaded (feet in shade, tops in sun). Therefore having some other plants planted in front is a great way to accomplish this.

I like to interplant them around peonies, and with black eyed susans. Lilies peonies bloom together (atleast the asiatics) and then black eyed susans will take over.