One of the best tools that you have as gardeners to help us figure out 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.

A common way of figuring out when it's a good idea to plant fennel is to refer to the USDA zone info for Columbia.

Planting Calendar for Fennel

Frost tolerance for fennel:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since fennel do well in cold 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 Columbia 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 March 15 in Columbia. It might get as low as 10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Columbia may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Columbia last frost occurs after March 15 so make sure that you are prepared to cover your fennel if you have a surprise late frost.

USDA Zone Info for Columbia

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Columbia

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