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 reviewing the USDA zone info for Ottawa you should be able to determine when you can plant romaine lettuce.

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 quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant romaine lettuce in Ottawa 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 really do well. You can get started a little bit earlier by starting your romaine lettuce indoors.

Last Frost Date

The average date of last frost is April 15 in Ottawa. In the coldest months of winter you should expect an average low temperature of -10°F.

Keep in mind that USDA zone info for Ottawa is an average and the actual date of last frost changes from year to year. Since half of the time in Ottawa last frost occurs after April 15 be ready to cover your romaine lettuce in the event of one of those late frosts.

USDA Zone Info for Ottawa

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ottawa

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