Bought 2 hardy hibiscus syriacus plants - how long to wait before feeding? + red hibiscus in canada?

[Farcryjj]

Which part of Canada do you live? I live on the west coast, and during winter the coldest it gets is like -3 or -4 celcius. Would that still be bad?

OK, if the west coast winter is that mild, it might be ok to be planted in the yard. I'm in Montreal.