One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

By using the USDA zone info for Decorah you should be able to estimate when to plant calliopsis.

Planting Calendar for Calliopsis

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

It's probably not a good idea to plant calliopsis until after the last frost has passed because they require warm weather.

The earliest that you can plant calliopsis in Decorah 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 fully mature. You can get started a little bit earlier by starting your calliopsis indoors.

Last Frost Date

In Decorah the average date of last frost happens on May 15. You can expect an average low temperature of -25°F in the coldest months of winter.

Always keep in mind that USDA zone info for Decorah is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Decorah there is a last frost after May 15 so always be ready to protect your calliopsis in the event of a late frost.

USDA Zone Info for Decorah

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 Decorah

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