One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

The best time to plant petunias in Mandan should be estimated by looking at 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.

Since petunias are barely cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant petunias in Mandan 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 grow to maturity. If you are starting your petunias indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Mandan. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Mandan is just an average the actual date of last frost changes from year to year. Half of the time in Mandan you get surprised by a frost after May 15 so always be ready to cover your petunias in the event of one of those late frosts.

USDA Zone Info for Mandan

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 Mandan

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