Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Seattle can be reffered to in order to figure out 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.

Fennel do well in cold weather which tells us that you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant fennel in Seattle 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 couple of weeks earlier by starting your fennel indoors.

Last Frost Date

In Seattle the average date of last frost happens on March 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 just an average because it is based on the USDA zone info for Seattle and it will vary from year to year. Half of the time in Seattle you get a frost after March 15 so just be sure to be ready to protect your fennel in the event of a surprise late frost.

USDA Zone Info for Seattle

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Seattle

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