When do they bloom? Mine have not bloomed yet and it is August. We are in a zone 8 growing area.
Hyacinth Bean Plants
Certified GKH Gardening Expert
Hyacinth Bean Vines can have little to no flowers if the nitrogen level is too high or you fertilize with too high of a nitrogen ratio fertilizer. Hyacinth Bean plants produce their own nitrogen so additional fertilizer is not usually needed.
They also do not tend to produce many flowers in summer, but will began bloom when the weather cools in late summer, early autumn.
Full sun is needed for a healthy, happy blooming vine.
Here is a link with more information.