One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Charleston can be looked at to figure out when you can plant saxifraga.

Planting Calendar for Saxifraga

Frost tolerance for saxifraga:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since saxifraga are barely cold tolerant you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant saxifraga 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 saxifraga and expect a good harvest is probably September. If you wait any later than that and your saxifraga may not have a chance to really do well. If you are starting your saxifraga indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Charleston the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 20°F.

Keep in mind that USDA zone info for Charleston may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Charleston last frost occurs after February 15 be ready to cover your saxifraga in the event of one of those late frosts.

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.