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

You can determine when to plant petunias in Roselle by referring to 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 means that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant petunias in Roselle 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

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

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Roselle and it changes from year to year. Half of the time in Roselle it frosts late in the year after April 15 so always be ready to cover your petunias in the event of one of those late frosts.

USDA Zone Info for Roselle

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Roselle

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