Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 petunias in Sullivan should be determined by looking at the USDA zone info.

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.

Petunias are barely cold tolerant which tells us that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant petunias in Sullivan 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. You probably don't want to wait any later than that or else 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 little bit earlier.

Last Frost Date

In Sullivan the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 5°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Sullivan and it is different every year. Since half of the time in Sullivan it frosts late in the year after April 15 be ready to protect your petunias in the event of a surprise late frost.

USDA Zone Info for Sullivan

Here is the info for USDA Zone 7b.

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

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Sullivan

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