One of the first steps you take when you are figuring out 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.

You will be able to estimate when it's the best time to plant romanesco by looking at the USDA zone info for Suisun City.

Planting Calendar for Romanesco

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

Romanesco do ok in mild cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant romanesco in Suisun City 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. If you wait any later than that and your romanesco may not have a chance to fully mature. Starting your romanesco indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Suisun City. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Suisun City is just an average the actual date of last frost will vary from year to year. Since half of the time in Suisun City you get a frost after February 15 be ready to cover your romanesco in the event of one of those late frosts.

USDA Zone Info for Suisun 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 Suisun City

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