One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant fennel in Napa should be figured out by referring to 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.

Fennel tend to make it in quite a bit of cold which means that you can plant them much earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant fennel in Napa is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant fennel and expect a good harvest is probably October. You probably don't want to wait any later than that or else your fennel may not have a chance to fully mature. Starting your fennel indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Napa. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Napa may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Napa you get surprised by a frost after February 15 so be sure to be ready to cover your fennel if you have a surprise late frost.

USDA Zone Info for Napa

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Napa

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