First I have to say that the pics in this blog are not mine. I don't remember where I got them. Somewhere online during my research on the subject. I apologize if I have used your photo and offended you. Please let me know and I will gladly remove it.
The plants are not hardy enough to stay outdoors all winter anywhere in Canada, unfortunately. I treat them like canna lilies, callas, glads, dahlias and bring them into the basement/garage/root cellar after they go dormant in the fall.
They do well in a large pot in the summer or you can plant them directly into the ground. If they are in a pot you can simply use a dolly to wheel the pot into the cold storage area. If they are in the ground they can be dug up, the root ball placed into a garbage bag and then stored for the winter after they go dormant in the fall. When the outside temperature is steady at the same temp as the storage area, they can go back outside to wake up in their own time when the temps are steadily above freezing. You can also bring them indoors, potted, and wake them up early if they are small enough.
It's very important that the roots do not freeze at any time! Your cold storage area needs to be cold and dark and always above freezing! The dark and cold are important to keep them domant for the winter. Semi-dryness is important too. Just a little water every month is all that's needed. Too wet and they will rot and die.
They can be grown as houseplants through the winter, if you have enough light and space but they usually attract red spider mites long before spring comes and just don't stay very healthy indoors.
It may sound like a lot of trouble to go to for one plant, but if you have ever seen a large one in person, you will understand how truly stunning these really are!
They are also extremely poisonous so be careful with the leaves and sap and wash your hands well after handling.
These (left) are my current brugmanias. You may have seen them growing in my indoor grow room in the previous post. I got stem pieces in a trade, rooted them and now have several around 2' tall. I grew them to about that height under lights this fall/winter then put them into the basement cold storage to go dormant until I can put them outside in the spring. I needed the room under the lights.
They are super easy to root in water and grow from stem cuttings. The important thing to remember is to keep the water always warm! Never let it get cold. You can often find growers in the fall who have cuttings available since they usually cut them back before bringing inside.
A close relative of the brugmansia is the datura, also occasionally called "angel's trumpet". You can tell the difference by the flower growth. Brugmansia flowers always hang down and datura bloom always stick up. Daturas are annuals that stay low to the ground and spread, while brugs are woody tree like forms, especially if you remove the suckers. Daturas are true annuals, regrowing every season from seed. It's difficult to keep them over the winter but they are very fast growers!
They come in a few colours, usually variations of white or purple and some blue, with single or double blooms.
Like brugmansia, every part of the plant is deadly poisonous! But they are are beautiful!