One of the first steps you take when you are determining your gardening schedule is find your 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 Waterloo should be used to figure out when you can 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 start planting them much earlier than plants that are more sensitive to the cold.

The earliest that you can plant fennel in Waterloo 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. You can get started a couple of weeks earlier by starting your fennel indoors.

Last Frost Date

In Waterloo the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Waterloo is an average and the actual date of last frost changes from year to year. Half of the time in Waterloo you get a frost after April 15 so make sure that you are prepared to cover your fennel if you have a surprise late frost.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Waterloo

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