Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for San Ramon you should be able to estimate when it's the best time to plant corn.

Planting Calendar for Corn

Frost tolerance for corn:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's a bad idea to plant corn until after the last frost when the weather gets warmer because they do not do well in cold weather.

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

The last month that you can plant corn and expect a good harvest is probably September. Any later than that and your corn may not have a chance to really do well. Starting your 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 February 15 in San Ramon. In the coldest months of winter you can expect an average low temperature of 25°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for San Ramon and it will vary from year to year. Since half of the time in San Ramon there is a last frost after February 15 be ready to protect your corn if you have a surprise late frost.

USDA Zone Info for San Ramon

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 San Ramon

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