One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

By looking at the USDA zone info for Ontario it's a good idea to determine when it's a good idea to plant lettuce.

Planting Calendar for Lettuce

Frost tolerance for lettuce:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant lettuce a little earlier in the year because they do well in moderate cold.

The earliest that you can plant lettuce in Ontario 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 lettuce and expect a good harvest is probably September. You probably don't want to wait any later than that or else your lettuce may not have a chance to really do well. You can get started a little bit earlier by starting your lettuce indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Ontario. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Ontario is just an average and the actual date of last frost will vary from year to year. Since half of the time in Ontario you get surprised by a frost after April 15 be ready to protect your lettuce in the event of a surprise late frost.

USDA Zone Info for Ontario

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Ontario

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