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.

By checking out the USDA zone info for Grand Forks you will be able to figure out when you can plant calliopsis.

Planting Calendar for Calliopsis

Frost tolerance for calliopsis:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Calliopsis are not cold tolerant which means that it is important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant calliopsis in Grand Forks 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 calliopsis and expect a good harvest is probably August. You probably don't want to wait any later than that or else your calliopsis may not have a chance to really do well. Starting your calliopsis indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Grand Forks is just an average the actual date of last frost changes from year to year. Half of the time in Grand Forks there is a last frost after May 15 so be sure to be ready to protect your calliopsis in the event of a late frost.

USDA Zone Info for Grand Forks

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 Grand Forks

You may be interested in your other planting guides for Grand Forks.