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.

It's a good idea to estimate when it's a good idea to plant corn by checking out the USDA zone info for Sonora.

Planting Calendar for Corn

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

Since corn require warm weather it is important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant corn in Sonora 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. You probably don't want to wait any later than that or else your corn may not have a chance to grow to maturity. If you are starting your corn indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Sonora the average date of last frost happens on February 15. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Sonora is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Sonora last frost occurs after February 15 so make sure that you are prepared to protect your corn if you have a late frost.

USDA Zone Info for Sonora

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 Sonora

You may be interested in your other planting guides for Sonora.