Yep, I saw these plants in botany garden of Bydgoszcz's Casimir the Great University. If these plants can survive in Poland (that, you know, has winters and all) it can totally grow anywhere.
I have a angel trumpet for almost 3 years now. Hes only given me 3 flowers. I just realised i never gave a good fertiliser. You mentioned miloganite. What else can you suggest? Soil wise? Great video thanks.
Angel Trumpets are poisonous. DONT EAT. So many common ormanental plants are not safe to eat, Foxglove, Oleander and Hemlock. Watch kids and pets around them. Keep them out of flowerbeds. Again, beautiful to look at. Not for consuming.