One of the best tools that you have as gardeners to help us estimate 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 figuring out when it's the best time to plant petunias is to look at the USDA zone info for Rock Hill.

Planting Calendar for Petunias

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

You can plant petunias just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant petunias in Rock Hill 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 petunias and expect a good harvest is probably August. Any later than that and your petunias may not have a chance to really do well. If you are starting your petunias indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Rock Hill. It might get as low as 10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Rock Hill is just an average and the actual date of last frost changes from year to year. Since half of the time in Rock Hill last frost occurs after March 15 be ready to protect your petunias if you have a surprise late frost.

USDA Zone Info for Rock Hill

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Rock Hill

You may be interested in your other planting guides for Rock Hill.