One of the first steps you take when you are estimating 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.

The first opportunity to plant calliopsis in Polson should be determined by using the USDA zone info.

Planting Calendar for Calliopsis

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

Calliopsis require warm weather which means 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 Polson 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. If you wait 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 few weeks earlier.

Last Frost Date

In Polson the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Polson is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Polson you get a frost after April 15 so make sure that you are ready to protect your calliopsis in the event of one of those late frosts.

USDA Zone Info for Polson

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Polson

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