One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant potatos in Ontario should be determined by looking at the USDA zone info.

Planting Calendar for Potatos

Frost tolerance for potatos:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Potatos are very cold tolerant which means that you can plant them much earlier than plants that are more sensitive to the cold.

The earliest that you can plant potatos in Ontario is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant potatos and expect a good harvest is probably October. You probably don't want to wait any later than that or else your potatos may not have a chance to fully mature. If you are starting your potatos indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Ontario. It might get as low as 30°F during the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Ontario and it is different every year. Half of the time in Ontario it frosts late in the year after January 31 so make sure that you are prepared to protect your potatos if you have a surprise late frost.

USDA Zone Info for Ontario

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Ontario

You may be interested in your other planting guides for Ontario.