One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when it's the best time to plant calliopsis by checking out the USDA zone info for Superior.

Planting Calendar for Calliopsis

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

Since calliopsis require warm weather you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant calliopsis in Superior 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. Any later than that and your calliopsis may not have a chance to grow to maturity. If you are starting your calliopsis indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Superior. In the coldest months of winter you should expect an average low temperature of -25°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Superior and it is different every year. Half of the time in Superior last frost occurs after May 15 so be sure to be ready to cover your calliopsis in the event of a surprise late frost.

USDA Zone Info for Superior

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Superior

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