One of the first steps you take when you are estimating your gardening schedule is find your 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.

It's possible to figure out when to plant rosemary by referring to the USDA zone info for Charleston.

Planting Calendar for Rosemary

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

Rosemary do well in cold which means that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant rosemary in Charleston 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 rosemary and expect a good harvest is probably October. If you wait any later than that and your rosemary may not have a chance to fully mature. If you are starting your rosemary indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Charleston. In the coldest months of winter you can expect an average low temperature of 20°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Charleston and it changes from year to year. Half of the time in Charleston there is a last frost after February 15 so make sure that you are ready to protect your rosemary if you have 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.