The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 should be used to estimate when you can plant tall phlox.

Planting Calendar for Tall Phlox

Frost tolerance for tall phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since tall phlox are moderately cold tolerant you can plant them just a bit earlier in the year than more sensitive plants.

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

Last Frost Date

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

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Charleston and it is different every year. Since half of the time in Charleston you get a frost after April 15 be ready to cover your tall phlox in the event of 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.