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.

You should be able to determine when it's the best time to plant petunias by looking at the USDA zone info for Montevideo.

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 get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant petunias in Montevideo 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. If you wait any later than that and your petunias may not have a chance to fully mature. You can get started a few weeks earlier by starting your petunias indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Montevideo. It might get as low as -25°F during the coldest months of winter.

It's important to remember that USDA zone info for Montevideo is an average and the actual date of last frost changes from year to year. Half of the time in Montevideo you get surprised by a frost after May 15 so just be sure to be ready to cover your petunias in the event of a surprise late frost.

USDA Zone Info for Montevideo

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Montevideo

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