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.

The USDA zone info for San Diego can be looked at to determine when 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.

You can plant sweet corn just a tiny 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. If you wait any later than that and your sweet corn may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your sweet corn indoors.

Last Frost Date

The average date of last frost is February 15 in San Diego. It might get as low as 20°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for San Diego and it will vary from year to year. Since half of the time in San Diego there is a last frost after February 15 be ready to cover your sweet corn if you have one of those late frosts.

USDA Zone Info for San Diego

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in San Diego

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