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.

In Rialto you can figure out when it's possible to plant corn by looking at the USDA zone info.

Planting Calendar for Corn

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

It's a bad idea to plant corn until after all chance of frost has passed because they require warm weather.

The earliest that you can plant corn in Rialto 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 corn and expect a good harvest is probably September. Any later than that and your corn may not have a chance to fully mature. Starting your corn indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Rialto. In the coldest months of winter you can expect an average low temperature of 30°F.

Since the USDA zone info for Rialto is just an average the actual date of last frost is different every year. Since half of the time in Rialto you get a frost after January 31 be ready to cover your corn if you have a late frost.

USDA Zone Info for Rialto

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Rialto

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