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.

The first chance to plant impatiens in Charleston should be figured out by using the USDA zone info.

Planting Calendar for Impatiens

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

It's a bad idea to plant impatiens until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant impatiens in Charleston is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant impatiens and expect a good harvest is probably August. You probably don't want to wait any later than that or else your impatiens may not have a chance to really do well. If you are starting your impatiens indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Charleston the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Charleston is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Charleston last frost occurs after April 15 be ready to protect your impatiens 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.