Hi Nelson:
I have not grown this plant myself but there is an article about growing it in Canada here:
http://canada-gardens.com/2pawpaw.html
Hope this helps.

Thank you for the link. I bought two pawpaw plants frum humbernurseries and I guess my condo was a bit to warm this winter cause they already grew about 8" since mid feb. I was told by the guys at Rhoras nut farm that davis pawpaw's should survive in toronto and that there is a pawpaw tree at the mount pleasant cemetery that has survived for many years. So This spring I will plant two in my parents backyard and see what happens.