One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant fennel in Spearfish should be determined by looking at 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.

Since fennel are very cold tolerant you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant fennel in Spearfish 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. You probably don't want to wait any later than that or else your fennel may not have a chance to really do well. If you are starting your fennel indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Spearfish. You can expect an average low temperature of -20°F in the coldest months of winter.

Always keep in mind that USDA zone info for Spearfish is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Spearfish it frosts late in the year after April 15 so just be sure to be ready to cover your fennel if you have one of those late frosts.

USDA Zone Info for Spearfish

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Spearfish

You may be interested in your other planting guides for Spearfish.