One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant calibrachoa in Petersburg can be determined by checking out the USDA zone info.

Planting Calendar for Calibrachoa

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

You can plant calibrachoa just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant calibrachoa 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 calibrachoa and expect a good harvest is probably August. If you wait any later than that and your calibrachoa may not have a chance to fully mature. You can get started a little bit earlier by starting your calibrachoa indoors.

Last Frost Date

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

Keep in mind that USDA zone info for Petersburg is an average and the actual date of last frost changes from year to year. Half of the time in Petersburg it frosts late in the year after April 15 so just be sure to be ready to cover your calibrachoa 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.