The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Indiana should be looked at to determine when it's the best time to plant petunias.

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.

Since petunias do ok in moderate cold you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant petunias in Indiana 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. You can get started a few weeks earlier by starting your petunias indoors.

Last Frost Date

The average date of last frost is April 15 in Indiana. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Indiana is just an average the actual date of last frost changes from year to year. Half of the time in Indiana last frost occurs after April 15 so make sure that you are ready to cover your petunias if you have a late frost.

USDA Zone Info for Indiana

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 Indiana

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