Posted: 11/08/2013 at 11:04
Hi Stacy, the Kew site says the following:
"Turkish sage is a hardy species of Phlomis, which can be grown in any good, well-drained soil, in sun or partial shade. It has a long flowering-period, stretching from late spring to early autumn. It does well in sunny borders in British gardens, and is drought tolerant when established. Propagation can be carried out by division of the clumps."
So it sounds like it doesn't really matter whether sun or partial shade. Apparently it does spread underground though.