Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when it's the best time to plant romanesco in National City by referring to the USDA zone info.

Planting Calendar for Romanesco

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

Since romanesco do well in moderate cold you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant romanesco in National 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. Any later than that and your romanesco may not have a chance to grow to maturity. Starting your romanesco indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on January 31 in National City. In the coldest months of winter you should expect an average low temperature of 35°F.

Since the USDA zone info for National City is just an average the actual date of last frost is different every year. Half of the time in National City last frost occurs after January 31 so be sure to be ready to cover your romanesco in the event of one of those late frosts.

USDA Zone Info for National City

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in National City

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