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

You should be able to estimate when it's a good idea to plant petunias by referring to the USDA zone info for Ironwood.

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 plant them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant petunias in Ironwood is April. However, you really should wait until May 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. Starting your petunias indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Ironwood. In the coldest months of winter you can expect an average low temperature of -30°F.

It's important to remember that USDA zone info for Ironwood is an average and the actual date of last frost is different every year. Half of the time in Ironwood there is a last frost after May 15 so just be sure to be ready to protect your petunias in the event of one of those late frosts.

USDA Zone Info for Ironwood

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Ironwood

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