Hi, looks like you are in zone 4b...anyone? please correct if this is wrong!

There's a nice Canadian Zone map here. If you click on the newest 2000 one and zoom to Ottawa, it is listed as a Canadian Zone 5a, which is probably around a USDA 4 or so.

Thank you both Pewterdigit and Jenny - that was good advice, and those maps are great. In the meantime the cornflowers (blue, pink and white!) have started to bloom on my balcony. I love my little rookie garden out there, and start to think about autumn and winter, which makes the hardiness zone important.

Viennawoods, Ottawa is a beautiful place, but cold there in the winter, snow in May is not uncommon. Hope you like it there, Canada is really a beautiful country. Where in Ottawa do you live? There's a big difference between living over the Rideau Canal, for example, and the country surrounding the city.

Hi Karen,
Yes I like Ottawa very much. This is my fourth year and my second one in the Westend. No May snow this year, although spring was cool and wet. Once summer arrives it is wonderful. I am on the seventh floor, facing East, no high buildings in front of me, just bungalows which are hidden under large old trees in summer. I see the peace tower on the horizon and watched the Canada day fireworks from my balcony. You seem to know the town well - did you ever live here?

Cold in Ottawa, eh? =) Not as cold as it gets here! You can grow a lot more plants than I can, too! And we've had snow in June and July! Anyways, not really bragging (I wish it was warmer here in the winter!). Are you growing any perennials on your balcony? In zone 5, you could be growing lilacs and loads of other zone 3 perennials.