Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for San Bernardino it's possible to estimate when it's the best time to plant columbine.

Planting Calendar for Columbine

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

Columbine do well in moderate cold which means that you can start planting them earlier than other frost tender plants.

The earliest that you can plant columbine in San Bernardino 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 really do well. You can get started a few weeks earlier by starting your columbine indoors.

Last Frost Date

The average date of last frost is February 15 in San Bernardino. In the coldest months of winter you can expect an average low temperature of 25°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for San Bernardino and it will vary from year to year. Half of the time in San Bernardino last frost occurs after February 15 so just be sure to be ready to cover your columbine if you have a surprise late frost.

USDA Zone Info for San Bernardino

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 San Bernardino

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