The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant calliopsis in Petaluma can be figured out 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 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 Petaluma 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. You probably don't want to wait any later than that or else your calliopsis may not have a chance to really do well. You can get started a few weeks earlier by starting your calliopsis indoors.

Last Frost Date

In Petaluma the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

It's important to remember that USDA zone info for Petaluma 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 Petaluma there is a last frost after February 15 be ready to protect your calliopsis if you have one of those late frosts.

USDA Zone Info for Petaluma

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 Petaluma

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