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

A way of estimating when you can plant borage is to consult the USDA zone info for Duluth.

Planting Calendar for Borage

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

Borage do well in moderate cold which tells us that you can plant them earlier than other frost tender plants.

The earliest that you can plant borage 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 borage and expect a good harvest is probably August. Any later than that and your borage may not have a chance to fully mature. Starting your borage indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Duluth the average date of last frost happens on May 15. You can expect an average low temperature of -30°F in the coldest months of winter.

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 borage 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.