One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for San Diego should be looked at to determine when it's a good idea to plant common hollyhock.

Planting Calendar for Common hollyhock

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

Since common hollyhock are moderately cold tolerant 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 common hollyhock 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 common hollyhock and expect a good harvest is probably October. You probably don't want to wait any later than that or else your common hollyhock may not have a chance to fully mature. If you are starting your common hollyhock indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In San Diego the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

Since the USDA zone info for San Diego is an average the actual date of last frost will vary from year to year. Since half of the time in San Diego you get surprised by a frost after February 15 be ready to protect your common hollyhock if you have a surprise late frost.

USDA Zone Info for San Diego

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in San Diego

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