One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant iceberg lettuce in Rialto can be figured out by reviewing the USDA zone info.

Planting Calendar for Iceberg lettuce

Frost tolerance for iceberg lettuce:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since iceberg lettuce are barely cold tolerant you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant iceberg lettuce 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 iceberg lettuce and expect a good harvest is probably September. Any later than that and your iceberg lettuce may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your iceberg lettuce indoors.

Last Frost Date

On average all chance of frost has passed is on January 31 in Rialto. It might get as low as 30°F during the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Rialto and it changes from year to year. Half of the time in Rialto it frosts late in the year after January 31 so just be sure to be ready to cover your iceberg lettuce if you have 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.