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

You will be able to estimate when you can plant calliopsis by reviewing the USDA zone info for Missoula.

Planting Calendar for Calliopsis

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

Calliopsis are not cold tolerant which tells us that you must wait until it warms up after the last frost before you can plant them.

The earliest that you can plant calliopsis in Missoula is April. However, you really should wait until May 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 fully mature. You can get started a few weeks earlier by starting your calliopsis indoors.

Last Frost Date

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

Just be sure to remember that USDA zone info for Missoula is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Missoula there is a last frost after April 15 so just be sure to be ready to cover your calliopsis if you have a late frost.

USDA Zone Info for Missoula

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Missoula

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