We've had a solandra for 2 years now (up against our chimney behind a jacaranda tree to the south), and it grows like crazy, but no flowers. It's in part shade and climbs well. Soil is heavily amended clay, but still clay. Slightly acid (I just tested ~6.2)

In googling this, I came across this nugget:

Cup of gold grows best with regular watering, but blooms best when water is withheld. Let the vine grow for a while, producing vigorous new shoots, then withhold water until the leaves begin to wilt.

Thoughts on any of this?