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.

In Rock Springs you can estimate when to plant calliopsis by reviewing the USDA zone info.

Planting Calendar for Calliopsis

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

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 Rock Springs 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 little bit earlier by starting your calliopsis indoors.

Last Frost Date

The average date of last frost is April 15 in Rock Springs. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Rock Springs is just an average the actual date of last frost is different every year. Half of the time in Rock Springs 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 Rock Springs

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Rock Springs

You may be interested in your other planting guides for Rock Springs.