One of the best tools that you have as gardeners to help us figure out 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 estimate when to plant spinach by checking out the USDA zone info.

Planting Calendar for Spinach

Frost tolerance for spinach:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since spinach are moderately cold tolerant you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant spinach in Rialto is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant spinach and expect a good harvest is probably October. You probably don't want to wait any later than that or else your spinach may not have a chance to fully mature. If you are starting your spinach indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Rialto. You can expect an average low temperature of 30°F in the coldest months of winter.

Keep in mind that USDA zone info for Rialto is just an average and the actual date of last frost changes from year to year. Since half of the time in Rialto there is a last frost after January 31 be ready to cover your spinach in the event of one of those late frosts.

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.