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.

It's a good idea to determine when it's a good idea to plant flower-of-an-hour by reviewing the USDA zone info for Petersburg.

Planting Calendar for Flower-of-an-Hour

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

Flower-of-an-Hour are barely cold tolerant which tells us that you can get them planted just a bit earlier than other frost tender plants.

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

Last Frost Date

In Petersburg the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

It's important to remember that USDA zone info for Petersburg is just an average and the actual date of last frost 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 flower-of-an-hour if you have a late frost.

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.