I've never had any luck with this plant but I did see quite a few growing in Puerto Rico last month. It must be a popular landscape plant over there. There were several huge vines in full bloom, all growing in full sun. I couldn't tell you anything else, sorry. Good luck.

I have a friend who owns a nursery, that has/had one - it's currently on display in a butterfly atrium. Her vine is MASSIVE ie it's in a 50 gallon container and of course, blooms every summer.

I got cuttings from her and asked how long before it would bloom - she said hers was a woody and huge vine before it finally bloomed, so I'd say (according to her description) it has to have a large caliper before it will bloom.