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.

The first opportunity to plant fennel in Riverside should be estimated 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.

Fennel can survive in a bit of cold which tells us 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 Riverside 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. Any later than that and your fennel may not have a chance to fully mature. If you are starting your fennel indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Riverside. In the coldest months of winter you should expect an average low temperature of -10°F.

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

USDA Zone Info for Riverside

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 Riverside

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