Have grown it both ways. Works well. A few years ago I discovered a large group of Petunia integrefolia growing and blooming in February in the footprint of a very old building which had burned in the Low Country of SC. Each plant was a single stem about 3' tall. Quite unusual. I collected seed. To date I have not been able to replicate the original plant characteristic of growing upright and mine continue to cascade in the normal manner unless supported. A mystery. I still have some seed if any southeners want to play around with it.

Thanks Nandina, any interest in letting a northerner play with that integrefolia seed?

Salpal, e-mail me an address. I will be happy to send you some seed. Hopefully some of the plants you raise will exhibit the unusual blossom patterns that caught my eye which are not common petunia characteristics.

nadina if you have any extra I would love to give them a try
Kiddo