One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's possible to plant iceberg lettuce by reviewing the USDA zone info for Duluth.

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.

Since iceberg lettuce are barely cold tolerant you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant iceberg lettuce in Duluth 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 iceberg lettuce and expect a good harvest is probably August. Any later than that and your iceberg lettuce may not have a chance to grow to maturity. You can get started a little bit earlier by starting your iceberg lettuce indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Duluth. You should expect an average low temperature of 5°F in the coldest months of winter.

Remember that USDA zone info for Duluth is an average and the actual date of last frost changes from year to year. Since half of the time in Duluth you get a frost after April 15 be ready to protect your iceberg lettuce in the event of a surprise 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.