The USDA Zone info is a great tool for gardeners to help us estimate 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.

You can figure out when you can plant calendula in Duluth by reviewing the USDA zone info.

Planting Calendar for Calendula

Frost tolerance for calendula:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant calendula a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant calendula 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 calendula and expect a good harvest is probably August. If you wait any later than that and your calendula may not have a chance to fully mature. You can get started a few weeks earlier by starting your calendula indoors.

Last Frost Date

The average date of last frost is May 15 in Duluth. In the coldest months of winter you should expect an average low temperature of -30°F.

Since the USDA zone info for Duluth may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Duluth you get surprised by a frost after May 15 be ready to protect your calendula in the event of 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.