The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when to plant radishes in Ontario by reviewing the USDA zone info.

Planting Calendar for Radishes

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

Radishes do ok in pretty solid cold which means that you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant radishes 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 radishes and expect a good harvest is probably October. Any later than that and your radishes may not have a chance to grow to maturity. You can get started a little bit earlier by starting your radishes indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Ontario. In the coldest months of winter you should expect an average low temperature of 30°F.

It's important to remember that USDA zone info for Ontario is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Ontario you get surprised by a frost after January 31 be ready to cover your radishes 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.