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.

The earliest that you can plant romaine lettuce in Toronto should be estimated by using the USDA zone info.

Planting Calendar for Romaine lettuce

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

Since romaine lettuce are very cold tolerant you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant romaine lettuce 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 romaine lettuce and expect a good harvest is probably September. If you wait any later than that and your romaine lettuce may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your romaine lettuce indoors.

Last Frost Date

In Toronto the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Toronto may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Toronto it frosts late in the year after April 15 so make sure that you are ready to cover your romaine lettuce if you have 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.