One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of getting a good idea when to plant columbine is to refer to the USDA zone info for San Luis Obispo.

Planting Calendar for Columbine

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

Since columbine do well in moderate cold you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant columbine in San Luis Obispo 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. If you wait any later than that and your columbine may not have a chance to grow to maturity. Starting your columbine indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on February 15 in San Luis Obispo. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for San Luis Obispo is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in San Luis Obispo you get a frost after February 15 be ready to cover your columbine in the event of one of those late frosts.

USDA Zone Info for San Luis Obispo

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 Luis Obispo

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