The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to estimate when it's possible to plant astilbe by reviewing the USDA zone info for Petersburg.

Planting Calendar for Astilbe

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

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

The earliest that you can plant astilbe 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 astilbe and expect a good harvest is probably August. You probably don't want to wait any later than that or else your astilbe may not have a chance to grow to maturity. You can get started a little bit earlier by starting your astilbe indoors.

Last Frost Date

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

It's important to remember that USDA zone info for Petersburg is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Petersburg last frost occurs after April 15 be ready to cover your astilbe in the event of a surprise 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.