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 USDA zone info for Oak Forest should be reviewed to estimate when it's the best time to plant fennel.

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 a bit of cold which tells us that 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 Oak Forest 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. Any later than that and your fennel may not have a chance to fully mature. You can get started a few weeks earlier by starting your fennel indoors.

Last Frost Date

The average date of last frost is April 15 in Oak Forest. You should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Oak Forest is an average and the actual date of last frost changes from year to year. Since half of the time in Oak Forest it frosts late in the year after April 15 be ready to protect your fennel if you have a late frost.

USDA Zone Info for Oak Forest

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 Oak Forest

You may be interested in your other planting guides for Oak Forest.