One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to estimate when it's possible to plant columbine by referring to the USDA zone info for Petersburg.

Planting Calendar for Columbine

Frost tolerance for columbine:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant columbine a little bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant columbine in Petersburg is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant columbine and expect a good harvest is probably September. If you wait any later than that and your columbine may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your columbine indoors.

Last Frost Date

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

Always keep in mind that USDA zone info for Petersburg may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Petersburg you get a frost after April 15 be ready to cover your columbine in the event of 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.