One of the first steps you take when you are determining your gardening schedule is find your 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 Billings should be determined 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.

Since fennel are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant fennel in Billings 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 fennel and expect a good harvest is probably August. You probably don't want to wait any later than that or else your fennel may not have a chance to fully mature. Starting your fennel indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Billings the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Just be sure to remember that USDA zone info for Billings is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Billings you get surprised by a frost after May 15 so make sure that you are ready to cover your fennel in the event of a surprise late frost.

USDA Zone Info for Billings

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Billings

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