One of the first steps you take when you are figuring out 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 you can plant petunias by referring to the USDA zone info for Richland.

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 slightly earlier in the year than other frost tender plants.

The earliest that you can plant petunias in Richland 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. 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

In Richland the average date of last frost happens on April 15. You should expect an average low temperature of 0°F in the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Richland and it is different every year. Half of the time in Richland there is a last frost after April 15 so always be ready to protect your petunias if you have a late frost.

USDA Zone Info for Richland

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Richland

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