One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Zone 3b should be used to figure out 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 one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant romaine lettuce in Zone 3b 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. Any later than that and your romaine lettuce may not have a chance to fully mature. Starting your romaine lettuce indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Zone 3b the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -35°F.

Remember that USDA zone info for Zone 3b is just an average and the actual date of last frost will vary from year to year. Since half of the time in Zone 3b there is a last frost after May 15 be ready to cover your romaine lettuce in the event of a surprise late frost.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in your other planting guides for Zone 3b.