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.

In Riverside you can estimate when to plant corn by using the USDA zone info.

Planting Calendar for Corn

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

Corn require warm weather which tells us that it's important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant corn in Riverside 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. If you wait any later than that and 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 little bit earlier.

Last Frost Date

In Riverside the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Riverside may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Riverside you get surprised by a frost after February 15 be ready to cover your corn if you have a late frost.

USDA Zone Info for Riverside

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 Riverside

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