One of the best tools that you have as gardeners to help us estimate 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.

One way of getting a good idea when to plant romaine lettuce is to check out the USDA zone info for Sunnyvale.

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 do ok in cold weather which means that you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant romaine lettuce in Sunnyvale 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 romaine lettuce and expect a good harvest is probably September. You probably don't want to wait any later than that or else your romaine lettuce may not have a chance to grow to maturity. You can get started a little bit earlier by starting your romaine lettuce indoors.

Last Frost Date

In Sunnyvale the average date of last frost happens on March 15. It might get as low as 10°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Sunnyvale and it changes from year to year. Since half of the time in Sunnyvale there is a last frost after March 15 be ready to protect your romaine lettuce in the event of a late frost.

USDA Zone Info for Sunnyvale

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Sunnyvale

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