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 Sonoma you can figure out when you can plant calliopsis by looking at the USDA zone info.

Planting Calendar for Calliopsis

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

Calliopsis do not do well in cold weather which means that you must wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant calliopsis in Sonoma 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. Any later than that and your calliopsis may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your calliopsis indoors.

Last Frost Date

The average date of last frost is February 15 in Sonoma. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Sonoma is an average the actual date of last frost will vary from year to year. Since half of the time in Sonoma you get surprised by a frost after February 15 be ready to protect your calliopsis in the event of a late frost.

USDA Zone Info for Sonoma

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 Sonoma

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