One of the first steps you take when you are getting a good idea your gardening schedule is find your 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 figure out when you can plant fennel by looking at the USDA zone info for Warrenville.

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 much earlier than other frost tender plants.

The earliest that you can plant fennel in Warrenville 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. You probably don't want to wait any later than that or else your fennel may not have a chance to grow to maturity. If you are starting your fennel indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Warrenville. In the coldest months of winter you can expect an average low temperature of -15°F.

Always keep in mind that USDA zone info for Warrenville 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 Warrenville last frost occurs after April 15 so always be ready to protect your fennel in the event of a late frost.

USDA Zone Info for Warrenville

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 Warrenville

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