I'm in the country and I have had ROS for 2 years now. I also winter sowed them and they were about 6 or 8" when I planted them in the garden. I didn't expect them to make it but they did. Both are a lavender blue color. I had a white one but it died. They are both planted on the south side of my greenhouse and somewhat sheltered from the winds. They are slow to come up, I think it was June before I saw any signs of life. Hope this helps. Marg

My RoS was container grown (1 gallon) when I purchased it 9 years ago. It didn't seem to do well in the first two locations(!), so it is now on the south side of our garage and thriving. It is about 8 feet tall. I think they are very slow to grow when small.

In the Guelph area (z.5b) they can be seen flowering everywhere at this time of the year. I believe certain varieties can be very prolific self-seeders, too.