The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for San Francisco should be used to estimate when it's possible to plant sweet corn.

Planting Calendar for Sweet corn

Frost tolerance for sweet corn:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Sweet corn do ok in very little cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant sweet corn in San Francisco is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant sweet corn and expect a good harvest is probably September. If you wait any later than that and your sweet corn may not have a chance to grow to maturity. Starting your sweet corn indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on January 31 in San Francisco. You can expect an average low temperature of 35°F in the coldest months of winter.

Always keep in mind that USDA zone info for San Francisco is just an average and the actual date of last frost will vary from year to year. Since half of the time in San Francisco last frost occurs after January 31 be ready to cover your sweet corn if you have a late frost.

USDA Zone Info for San Francisco

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 San Francisco

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