When to Plant Fennel in Sterling, IL

Before planting it is a good idea to find your USDA Zone info to estimate 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 Sterling should be reffered to in order to estimate when 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 are very cold tolerant which means that you can plant them a quite a bit earlier than other frost tender plants.

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 Sterling 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 fully mature. You can get started a couple of weeks earlier by starting your fennel indoors.

Last Frost Date

In Sterling 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.

Since the USDA zone info for Sterling is just an average the actual date of last frost is different every year. Since half of the time in Sterling you get a frost after April 15 be ready to protect your fennel if you have a late frost.

USDA Zone Info for Sterling

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 Sterling

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