Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Toronto it's a good idea to estimate when to plant rosemary.

Planting Calendar for Rosemary

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

Rosemary do well in a bit of cold which tells us that you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant rosemary 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 rosemary and expect a good harvest is probably September. Any later than that and your rosemary may not have a chance to really do well. You can get started a little bit earlier by starting your rosemary indoors.

Last Frost Date

The average date of last frost is April 15 in Toronto. It might get as low as -5°F during the coldest months of winter.

Keep in mind that USDA zone info for Toronto is an average and the actual date of last frost changes from year to year. Half of the time in Toronto it frosts late in the year after April 15 so be sure to be ready to cover your rosemary in the event of a 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.