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 estimate when it's the best time to plant fennel by using the USDA zone info for Marinette.

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 other frost tender plants.

The earliest that you can plant fennel in Marinette 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 grow to maturity. You can get started a couple of weeks earlier by starting your fennel indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Marinette. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Marinette may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Marinette there is a last frost after April 15 so always be ready to protect your fennel in the event of a surprise late frost.

USDA Zone Info for Marinette

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Marinette

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