One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Zone 10b you will be able to determine when it's possible 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 tend to make it in pretty solid cold which tells us that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant romaine lettuce in Zone 10b 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. If you wait any later than that and 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

On average the last frost has passed is on January 31 in Zone 10b. You should expect an average low temperature of 35°F in the coldest months of winter.

Remember that USDA zone info for Zone 10b is not always accurate and the actual date of last frost is different every year. Since half of the time in Zone 10b you get a frost after January 31 be ready to protect your romaine lettuce if you have one of those late frosts.

USDA Zone Info for Zone 10b

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Zone 10b

You may be interested in your other planting guides for Zone 10b.