One of the first steps you take when you are determining your gardening schedule is find your 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.

It's possible to figure out when it's the best time to plant violas by referring to the USDA zone info for Charleston.

Planting Calendar for Violas

Frost tolerance for violas:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since violas are one of those plants that can tolerate quite a bit of cold weather you can plant them much earlier in the year than more sensitive plants.

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

The last month that you can plant violas and expect a good harvest is probably October. Any later than that and your violas may not have a chance to grow to maturity. Starting your violas indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Charleston. It might get as low as 20°F during the coldest months of winter.

Keep in mind 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 can change quite a bit from year to year. Since half of the time in Charleston you get surprised by a frost after February 15 be ready to cover your violas if you have a surprise late frost.

USDA Zone Info for Charleston

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Charleston

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