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.

It's a good idea to figure out when you can plant fennel by referring to the USDA zone info for Onalaska.

Planting Calendar for Fennel

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

Fennel can survive in cold weather which means that you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant fennel in Onalaska 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. Any later than that and your fennel may not have a chance to really do well. You can get started a couple of weeks earlier by starting your fennel indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Onalaska. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Onalaska is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Onalaska last frost occurs after May 15 be ready to cover your fennel in the event of one of those late frosts.

USDA Zone Info for Onalaska

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 Onalaska

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