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.

You should be able to figure out when you can plant petunias by referring to the USDA zone info for Collinsville.

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 can survive in a tiny bit of cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant petunias in Collinsville 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 fully mature. Starting your petunias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Collinsville the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Collinsville and it will vary from year to year. Half of the time in Collinsville it frosts late in the year after April 15 so be sure to be ready to protect your petunias if you have one of those late frosts.

USDA Zone Info for Collinsville

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Collinsville

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