The USDA Zone info is a great tool for gardeners to help us estimate 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.

You should be able to figure out when you can plant romanesco by reviewing the USDA zone info for Petaluma.

Planting Calendar for Romanesco

Frost tolerance for romanesco:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since romanesco are moderately cold tolerant you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant romanesco in Petaluma is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant romanesco and expect a good harvest is probably October. Any later than that and your romanesco may not have a chance to really do well. You can get started a few weeks earlier by starting your romanesco indoors.

Last Frost Date

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

Just be sure to remember that USDA zone info for Petaluma is not always accurate and the actual date of last frost is different every year. Half of the time in Petaluma you get surprised by a frost after February 15 so just be sure to be ready to cover your romanesco in the event of a surprise late frost.

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.