Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant common hollyhock in Cupertino can be estimated by checking out the USDA zone info.

Planting Calendar for Common hollyhock

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

Common hollyhock can survive in a little bit of cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant common hollyhock in Cupertino 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. If you wait any later than that and 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 Cupertino the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Remember that USDA zone info for Cupertino is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Cupertino last frost occurs after February 15 so make sure that you are prepared to cover your common hollyhock in the event of one of those late frosts.

USDA Zone Info for Cupertino

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 Cupertino

You may be interested in your other planting guides for Cupertino.