One of the best tools that you have as gardeners to help us estimate 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.

By using the USDA zone info for Atherton you should be able to figure out when you can plant romanesco.

Planting Calendar for Romanesco

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

Romanesco can survive in mild cold which tells us that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant romanesco in Atherton 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. You probably don't want to wait any later than that or else your romanesco may not have a chance to grow to maturity. If you are starting your romanesco indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Keep in mind that USDA zone info for Atherton is not always accurate and the actual date of last frost changes from year to year. Half of the time in Atherton it frosts late in the year after February 15 so be sure to be ready to protect your romanesco in the event of a late frost.

USDA Zone Info for Atherton

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 Atherton

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