When to Plant Fennel in Vernon Hills, IL

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 Vernon Hills should be read to determine when it's possible 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.

You can plant fennel earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant fennel
Possibly ok, but a risky time to plant fennel
Probably not a good time to plant fennel

The earliest that you can plant fennel in Vernon Hills 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 grow to maturity. Starting your fennel indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Vernon Hills the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Vernon Hills and it changes from year to year. Since half of the time in Vernon Hills you get a frost after April 15 be ready to protect your fennel if you have a surprise late frost.

USDA Zone Info for Vernon Hills

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 Vernon Hills

You may be interested in your other planting guides for Vernon Hills.