The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when you can plant fennel in Ontario by checking out the USDA zone info.

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 quite a bit earlier in the year because they do well in cold.

The earliest that you can plant fennel in Ontario 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 grow to maturity. You can get started a little bit earlier by starting your fennel indoors.

Last Frost Date

In Ontario the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Ontario and it can change quite a bit from year to year. Half of the time in Ontario it frosts late in the year after April 15 so just be sure to be ready to cover your fennel if you have a surprise late frost.

USDA Zone Info for Ontario

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 Ontario

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