It is indeed interesting how variable are the ways people grow their bulbs!
I looked at the Wild Ginger website and saw the instructions about how to
grow C. mackenii : " Grow in partial sun in moist, well-drained soil. Keep
drier in winter and protect from cold. " I grow this plant in shallow, very
fast draining soil. In summer, it gets direct sun almost all day and in
winter it is partially shaded. And this is southern California, not Oregon!
Finally, this is the season it demands extra water here! Flowers were
drooping after our long dry spell.

I have treated this plant as a very drought tolerant one and it does not
seem to complain. So, it appears to be one tolerant of a rather wide range
of conditions.

Andrew
San Diego