One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

In Petersburg you can determine when to plant echinacea by reviewing the USDA zone info.

Planting Calendar for Echinacea

Frost tolerance for echinacea:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Echinacea are barely cold tolerant which tells us that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant echinacea in Petersburg 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 echinacea and expect a good harvest is probably August. If you wait any later than that and your echinacea may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your echinacea indoors.

Last Frost Date

The average date of last frost is April 15 in Petersburg. You can expect an average low temperature of 5°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Petersburg and it will vary from year to year. Since half of the time in Petersburg there is a last frost after April 15 be ready to protect your echinacea if you have one of those late frosts.

USDA Zone Info for Petersburg

Here is the info for USDA Zone 7b.

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

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

Plants to Grow in Petersburg

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