The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of making a decision about when you can plant romaine lettuce is to check out the USDA zone info for Bismarck.

Planting Calendar for Romaine lettuce

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

Romaine lettuce are very cold tolerant which tells us that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant romaine lettuce in Bismarck is March. However, you really should wait until April 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 August. You probably don't want to wait any later than that or else your romaine lettuce may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your romaine lettuce indoors.

Last Frost Date

In Bismarck the average date of last frost happens on May 15. You should expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Bismarck is not always accurate the actual date of last frost changes from year to year. Half of the time in Bismarck there is a last frost after May 15 so always be ready to protect your romaine lettuce if you have a late frost.

USDA Zone Info for Bismarck

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°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 -25°F.

Plants to Grow in Bismarck

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