The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Calexico should be reviewed to estimate when to plant romaine lettuce.

Planting Calendar for Romaine lettuce

Frost tolerance for romaine lettuce:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Romaine lettuce can survive in quite a bit of cold which means that you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant romaine lettuce in Calexico 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 romaine lettuce and expect a good harvest is probably October. You probably don't want to wait any later than that or else your romaine lettuce may not have a chance to fully mature. You can get started a few weeks earlier by starting your romaine lettuce indoors.

Last Frost Date

In Calexico the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 30°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Calexico and it will vary from year to year. Since half of the time in Calexico it frosts late in the year after January 31 be ready to cover your romaine lettuce in the event of a late frost.

USDA Zone Info for Calexico

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 Calexico

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