Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 estimating when to plant petunias is to look at the USDA zone info for Topeka.

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 do ok in moderate cold which means that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant petunias in Topeka 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. Any later than that and your petunias may not have a chance to really do well. You can get started a couple of weeks earlier by starting your petunias indoors.

Last Frost Date

The average date of last frost is April 15 in Topeka. You should expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that USDA zone info for Topeka is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Topeka you get surprised by a frost after April 15 be ready to cover your petunias in the event of a surprise late frost.

USDA Zone Info for Topeka

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Topeka

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