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

You can estimate when it's the best time to plant sweet corn in San Diego by reviewing the USDA zone info.

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.

You can plant sweet corn a bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant sweet corn in San Diego 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. You probably don't want to wait any later than that or else 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 the last frost when the weather gets warmer is on January 31 in San Diego. In the coldest months of winter you should expect an average low temperature of 35°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Diego and it will vary from year to year. Half of the time in San Diego last frost occurs after January 31 so just be sure to be ready to cover your sweet corn in the event of one of those late frosts.

USDA Zone Info for San Diego

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 Diego

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