The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant columbine in Duluth can be determined by looking at the USDA zone info.

Planting Calendar for Columbine

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

You can plant columbine a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant columbine 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 columbine and expect a good harvest is probably August. You probably don't want to wait any later than that or else your columbine may not have a chance to grow to maturity. If you are starting your columbine indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Keep in mind 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. Since half of the time in Duluth last frost occurs after May 15 be ready to protect your columbine if you have a 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.