Before planting it is a good idea to find your USDA Zone info to estimate 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 best time to plant iceberg lettuce in Ontario should be figured out by checking out the USDA zone info.

Planting Calendar for Iceberg lettuce

Frost tolerance for iceberg lettuce:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Iceberg lettuce can survive in mild cold which means that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant iceberg 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 iceberg lettuce and expect a good harvest is probably September. If you wait any later than that and your iceberg lettuce may not have a chance to really do well. If you are starting your iceberg lettuce indoors then you might be able to get away with starting them a couple of weeks earlier.

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.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Ontario and it can change quite a bit from year to year. Half of the time in Ontario it frosts late in the year after January 31 so make sure that you are ready to cover your iceberg lettuce if you have a 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.