Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 Irvine should be reffered to in order to estimate when it's the best time 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 can survive in a bit of cold which tells us that you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant fennel in Irvine 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. You can get started a few weeks earlier by starting your fennel indoors.

Last Frost Date

The average date of last frost is January 31 in Irvine. You can expect an average low temperature of 30°F in the coldest months of winter.

Remember that USDA zone info for Irvine is not always accurate and the actual date of last frost changes from year to year. Half of the time in Irvine you get surprised by a frost after January 31 so make sure that you are prepared to cover your fennel in the event of a late frost.

USDA Zone Info for Irvine

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Irvine

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