One of the first steps you take when you are estimating 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 figuring out when to plant calendula is to look at the USDA zone info for San Diego.

Planting Calendar for Calendula

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

Calendula can survive in moderate cold which means that 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 calendula in San Diego 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 calendula and expect a good harvest is probably October. Any later than that and your calendula may not have a chance to really do well. If you are starting your calendula indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is January 31 in San Diego. It might get as low as 35°F during the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for San Diego and it will vary from year to year. Half of the time in San Diego there is a last frost after January 31 so make sure that you are ready to protect your calendula if you have a late frost.

USDA Zone Info for San Diego

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in San Diego

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