The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant flower-of-an-hour in Charleston should be estimated by reviewing the USDA zone info.

Planting Calendar for Flower-of-an-Hour

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

You can plant flower-of-an-hour just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant flower-of-an-hour 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 flower-of-an-hour and expect a good harvest is probably August. Any later than that and your flower-of-an-hour may not have a chance to really do well. Starting your flower-of-an-hour indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Charleston. In the coldest months of winter you can expect an average low temperature of 0°F.

Remember that USDA zone info for Charleston is just an average and the actual date of last frost will vary from year to year. Half of the time in Charleston last frost occurs after April 15 so always be ready to cover your flower-of-an-hour if you have a surprise late frost.

USDA Zone Info for Charleston

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°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.