Here is some general info for USDA zone 3a to help you get started.
Average Date of Last Frost (spring) | May 15 |
Average Date of First Frost (fall) | September 15 |
Lowest Expected Low | -40°F |
Highest Expected Low | -35°F |
This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.
Below is a list of planting guides for Zone 3a.
Vegetables
Herbs
Flowers