One of the best tools that you have as gardeners to help us determine 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 USDA zone info for Duluth should be used to determine when to plant basil.

Planting Calendar for Basil

Frost tolerance for basil:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably a bad idea to plant basil until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant basil in Duluth is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant basil and expect a good harvest is probably August. If you wait any later than that and your basil may not have a chance to really do well. Starting your basil indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Duluth. You should expect an average low temperature of -30°F in 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 is different every year. Since half of the time in Duluth last frost occurs after May 15 be ready to protect your basil if you have a surprise late frost.

USDA Zone Info for Duluth

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 Duluth

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