One of the best tools that you have as gardeners to help us figure out 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.

The first chance to plant romaine lettuce in Duluth can be figured out by reviewing the USDA zone info.

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 one of those plants that can tolerate quite a bit of cold weather 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 Duluth 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 grow to maturity. You can get started a few weeks earlier by starting your romaine lettuce indoors.

Last Frost Date

The average date of last frost is April 15 in Duluth. It might get as low as 5°F during the coldest months of winter.

Since the USDA zone info for Duluth may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Duluth last frost occurs after April 15 so make sure that you are ready to protect your romaine lettuce in the event of a late frost.

USDA Zone Info for Duluth

Here is the info for USDA Zone 7b.

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

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

Plants to Grow in Duluth

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