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.

The USDA zone info for Charleston can be read to estimate when to plant lithospermum.

Planting Calendar for Lithospermum

Frost tolerance for lithospermum:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably a bad idea to plant lithospermum until after the last frost because they require warm weather.

The earliest that you can plant lithospermum in Charleston is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant lithospermum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your lithospermum may not have a chance to really do well. If you are starting your lithospermum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Charleston. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Charleston may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Charleston it frosts late in the year after February 15 be ready to protect your lithospermum in the event of a surprise late frost.

USDA Zone Info for Charleston

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Charleston

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