The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Toronto you can determine when to plant primroses by referring to the USDA zone info.

Planting Calendar for Primroses

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

Since primroses are very cold tolerant you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

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

The last month that you can plant primroses and expect a good harvest is probably September. Any later than that and your primroses may not have a chance to really do well. You can get started a few weeks earlier by starting your primroses indoors.

Last Frost Date

In Toronto the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Toronto and it can change quite a bit from year to year. Half of the time in Toronto you get a frost after April 15 so make sure that you are ready to protect your primroses in the event of a surprise late frost.

USDA Zone Info for Toronto

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Toronto

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