The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 determining when it's the best time to plant romaine lettuce is to refer to the USDA zone info for Charleston.

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 are one of those plants that can tolerate quite a bit of cold weather which means that you can plant them a quite a bit earlier than other frost tender plants.

The earliest that you can plant romaine lettuce in Charleston 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 few weeks earlier by starting your romaine lettuce indoors.

Last Frost Date

In Charleston the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Remember that USDA zone info for Charleston is just an average and the actual date of last frost is different every year. Half of the time in Charleston it frosts late in the year after April 15 so always be ready to protect your romaine lettuce if you have a late frost.

USDA Zone Info for Charleston

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Charleston

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