One of the best tools that you have as gardeners to help us figure out 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.

By checking out the USDA zone info for Charleston it's possible to figure out when it's a good idea to plant pearl onions.

Planting Calendar for Pearl onions

Frost tolerance for pearl onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant pearl onions a bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant pearl onions 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 pearl onions and expect a good harvest is probably August. You probably don't want to wait any later than that or else your pearl onions may not have a chance to grow to maturity. Starting your pearl onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Charleston. In the coldest months of winter you should expect an average low temperature of -10°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 will vary from year to year. Half of the time in Charleston you get a frost after April 15 so be sure to be ready to protect your pearl onions if you have one of those late frosts.

USDA Zone Info for Charleston

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°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.