Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Duluth it's a good idea to determine when it's possible to plant calibrachoa.

Planting Calendar for Calibrachoa

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

Since calibrachoa do ok in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant calibrachoa 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 calibrachoa and expect a good harvest is probably August. If you wait any later than that and your calibrachoa may not have a chance to grow to maturity. If you are starting your calibrachoa indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Duluth the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 5°F.

Always keep in mind that USDA zone info for Duluth is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Duluth there is a last frost after April 15 be ready to protect your calibrachoa in the event of one of those late frosts.

USDA Zone Info for Duluth

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Duluth

You may be interested in your other planting guides for Duluth.