I'm in Ontario, David, and used to live somewhat west of you which is why I asked. I know you are in Canadian Zone 5b but the USDA zone equivalents are sometimes a level lower. I asked because this Ag Canada map shows the USDA equivalent zones and I thought you looked to be closer to 4b but you would be able to place it more exactly. Zones don't go by latitude, the USDA system is based on minimum winter temperatures (the Canadian system takes more factors into account). I used to be Canadian zone 5 but USDA zone 4, however in the latest map incarnation I think I'm 4 on both, which makes it easier! Edit: Looking at this again with my laptop instead of iPad so I can zoom, it seems to show Peterborough right on the boundary of 4b and 5a, with areas below it in 5a except along the shoreline of Lake Ontario. This is on the new map, when I lived in that area it was designated as 4b on the previous map.
http://gmaps.nrcan.gc.ca/laasm...
