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 to plant dahlias in Duluth by using the USDA zone info.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost.

Dahlias do not do well in cold weather which means that it is important to wait until it warms up after all chance of frost has passed before you can plant them.

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

Last Frost Date

On average all chance of frost has passed is on May 15 in Duluth. In the coldest months of winter you should expect an average low temperature of -30°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Duluth and it will vary from year to year. Half of the time in Duluth there is a last frost after May 15 so just be sure to be ready to cover your dahlias 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.