From a resource I found online:

"Thunbergia spp.
Clockvine. Tender annual and perennial vines. T. alata (black-eyed Susan) and
T. gregorii are grown as summer annuals on a garden support or as a ground cover. T. grandiflora (Blue trumpet vine) and T. mysorensis are usually used as perennial vines in greenhouse displays for spring or fall blooms. Seeds germinate at 21 to 24ðC (70 to 75ðF), but seedlings
grow slowly. Softwood cuttings taken from new shoots root readily with bottom heat."