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.

You should be able to figure out when it's possible to plant romaine lettuce by using the USDA zone info for Manteca.

Planting Calendar for Romaine lettuce

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

Since romaine lettuce do well in cold you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant romaine lettuce in Manteca 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. Any later than that and your romaine lettuce may not have a chance to really do well. If you are starting your romaine lettuce indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

It's important to 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 Manteca and it changes from year to year. Since half of the time in Manteca last frost occurs after February 15 be ready to protect your romaine lettuce in the event of a late frost.

USDA Zone Info for Manteca

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 Manteca

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