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.

In Petersburg you can determine when it's a good idea to plant spearmint by using the USDA zone info.

Planting Calendar for Spearmint

Frost tolerance for spearmint:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Spearmint can survive in cold weather which means that you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant spearmint 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 spearmint and expect a good harvest is probably September. Any later than that and your spearmint may not have a chance to fully mature. If you are starting your spearmint indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Petersburg may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Petersburg there is a last frost after April 15 so make sure that you are ready to protect your spearmint 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.