The USDA Zone info is a great tool for gardeners to help us figure out 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.

A common way of estimating when you can plant columbine is to look at the USDA zone info for South San Francisco.

Planting Calendar for Columbine

Frost tolerance for columbine:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Columbine do ok in some cold which tells us that you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant columbine in South San Francisco 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 columbine and expect a good harvest is probably October. Any later than that and your columbine may not have a chance to grow to maturity. You can get started a little bit earlier by starting your columbine indoors.

Last Frost Date

The average date of last frost is January 31 in South San Francisco. In the coldest months of winter you can expect an average low temperature of 30°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for South San Francisco and it is different every year. Half of the time in South San Francisco you get a frost after January 31 so always be ready to protect your columbine if you have one of those late frosts.

USDA Zone Info for South San Francisco

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 South San Francisco

You may be interested in your other planting guides for South San Francisco.