Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's a good idea to plant purple coneflower in Duluth by referring to the USDA zone info.

Planting Calendar for Purple Coneflower

Frost tolerance for purple coneflower:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Purple Coneflower do ok in moderate cold which tells us that you can get them planted just a bit earlier than other frost tender plants.

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

The last month that you can plant purple coneflower and expect a good harvest is probably August. You probably don't want to wait any later than that or else your purple coneflower may not have a chance to fully mature. You can get started a little bit earlier by starting your purple coneflower indoors.

Last Frost Date

In Duluth the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Duluth is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Duluth there is a last frost after May 15 be ready to cover your purple coneflower in the event of one of those late frosts.

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.