One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

A common way of making a decision about when it's possible to plant rudbeckia is to consult the USDA zone info for Charleston.

Planting Calendar for Rudbeckia

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

You can plant rudbeckia just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant rudbeckia 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 rudbeckia and expect a good harvest is probably September. If you wait any later than that and your rudbeckia may not have a chance to fully mature. Starting your rudbeckia indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Charleston the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -5°F.

Since the USDA zone info for Charleston is just an average the actual date of last frost will vary from year to year. Since half of the time in Charleston you get a frost after April 15 be ready to protect your rudbeckia in the event of a late frost.

USDA Zone Info for Charleston

Here is the info for USDA Zone 6b.

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

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Charleston

You may be interested in your other planting guides for Charleston.