The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant gladiolus in Charleston should be figured out by using the USDA zone info.

Planting Calendar for Gladiolus

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

Since gladiolus are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant gladiolus 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 gladiolus and expect a good harvest is probably September. Any later than that and your gladiolus may not have a chance to really do well. You can get started a little bit earlier by starting your gladiolus indoors.

Last Frost Date

In Charleston the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Charleston and it changes from year to year. Half of the time in Charleston there is a last frost after February 15 so be sure to be ready to cover your gladiolus if you have one of those late frosts.

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.