One of the first steps you take when you are estimating 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.

A common way of figuring out when to plant petunias is to consult the USDA zone info for Rochester.

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 tend to make it in a tiny bit of cold which tells us that you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant petunias in Rochester 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. Starting your petunias indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Rochester the average date of last frost happens on May 15. You can expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Rochester may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Rochester it frosts late in the year after May 15 be ready to protect your petunias if you have a late frost.

USDA Zone Info for Rochester

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 Rochester

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