One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for San Bruno it's possible to estimate when it's the best time to plant radicchio.

Planting Calendar for Radicchio

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

You can plant radicchio a little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant radicchio in San Bruno 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 radicchio and expect a good harvest is probably October. If you wait any later than that and your radicchio may not have a chance to fully mature. If you are starting your radicchio indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in San Bruno. It might get as low as 30°F during the coldest months of winter.

Remember that USDA zone info for San Bruno is an average and the actual date of last frost is different every year. Since half of the time in San Bruno last frost occurs after January 31 be ready to protect your radicchio if you have a surprise late frost.

USDA Zone Info for San Bruno

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Bruno

You may be interested in your other planting guides for San Bruno.