The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant fennel in Petersburg can be figured out by using the USDA zone info.

Planting Calendar for Fennel

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

Fennel are one of those plants that can tolerate quite a bit of cold weather which means that you can get them planted much earlier than plants that are more sensitive to the cold.

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

Last Frost Date

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

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Petersburg and it can change quite a bit from year to year. Since half of the time in Petersburg it frosts late in the year after April 15 be ready to cover your fennel 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.