One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant calliopsis in Boulder City should be estimated by checking out the USDA zone info.

Planting Calendar for Calliopsis

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

You can not plant calliopsis until after the last frost because they are not cold tolerant.

The earliest that you can plant calliopsis in Boulder City is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant calliopsis and expect a good harvest is probably September. If you wait any later than that and your calliopsis may not have a chance to really do well. You can get started a couple of weeks earlier by starting your calliopsis indoors.

Last Frost Date

On average all chance of frost has passed is on February 15 in Boulder City. You can expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind that USDA zone info for Boulder City may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Boulder City last frost occurs after February 15 be ready to cover your calliopsis if you have one of those late frosts.

USDA Zone Info for Boulder City

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Boulder City

You may be interested in your other planting guides for Boulder City.