One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's a good idea to plant fennel by using the USDA zone info for Havre.

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 a lot earlier in the year than more sensitive plants.

The earliest that you can plant fennel in Havre 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 grow to maturity. You can get started a little bit earlier by starting your fennel indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Havre. In the coldest months of winter you should expect an average low temperature of -30°F.

Since the USDA zone info for Havre may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Havre you get surprised by a frost after May 15 be ready to cover your fennel if you have a surprise late frost.

USDA Zone Info for Havre

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Havre

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