Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to estimate when you can plant nasturtium by checking out the USDA zone info for Charleston.

Planting Calendar for Nasturtium

Frost tolerance for nasturtium:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Nasturtium are not cold tolerant which means that you must wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant nasturtium 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 nasturtium and expect a good harvest is probably September. If you wait any later than that and your nasturtium may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your nasturtium indoors.

Last Frost Date

On average the last frost is on February 15 in Charleston. You should 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 changes from year to year. Half of the time in Charleston last frost occurs after February 15 so make sure that you are ready to cover your nasturtium in the event of a 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.