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 USDA zone info for Duluth should be used to figure out when it's the best time to plant doronicum.

Planting Calendar for Doronicum

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

Doronicum are moderately cold tolerant which tells us that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant doronicum 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 doronicum and expect a good harvest is probably August. Any later than that and your doronicum may not have a chance to really do well. Starting your doronicum indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Duluth. It might get as low as -30°F during the coldest months of winter.

Always keep in mind that USDA zone info for Duluth is just an average and 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 doronicum 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.