One of the best tools that you have as gardeners to help us determine 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.

One way of figuring out when it's the best time to plant petunias is to use the USDA zone info for Calumet City.

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 do ok in moderate cold which tells us that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant petunias in Calumet City 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 grow to maturity. Starting your petunias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Calumet City. You can expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that USDA zone info for Calumet City may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Calumet City you get a frost after April 15 be ready to cover your petunias if you have a late frost.

USDA Zone Info for Calumet City

Here is the info for USDA Zone 6a.

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

Plants to Grow in Calumet City

You may be interested in your other planting guides for Calumet City.