One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of estimating when it's possible to plant calliopsis is to refer to the USDA zone info for Colby.

Planting Calendar for Calliopsis

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

You really shouldn't plant calliopsis until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant calliopsis in Colby 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. You can get started a couple of weeks earlier by starting your calliopsis indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Colby. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Colby is just an average the actual date of last frost will vary from year to year. Since half of the time in Colby last frost occurs after April 15 be ready to protect your calliopsis if you have a late frost.

USDA Zone Info for Colby

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 Colby

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