To determine when, what, and where to plant you will need to start with knowing the approximate last and first frosts of the season.
If you live in Alberta, Saskatchewan, or Manitoba this is a good resource:
Choose your city, or the one closest to you, and it will give you all the frosty information you need.
City of Origin
|Average number of frost-free days||120|
|Average date of last spring frost||May 21|
|Number of years last spring frost fell|
|Before May 31||16|
|Between June 1 – 15||3|
|After June 15||0|
|Average date of first fall frost||September 18|
|Number of years first frost fell|
|Before August 31||2|
|Between September 1 – 15||5|
|After September 15||12|
If you live outside the prairie provinces there are many other charts. Google is your friend. Search: Number of frost free days (city name) and you should find a chart that suits your needs.