One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Sonora you can estimate when to plant common hollyhock 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 do well in mild cold which tells us that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant common hollyhock in Sonora 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 grow to maturity. You can get started a few weeks earlier by starting your common hollyhock indoors.

Last Frost Date

In Sonora the average date of last frost happens on February 15. You can expect an average low temperature of 20°F in the coldest months of winter.

It's important to remember that USDA zone info for Sonora is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Sonora you get a frost after February 15 be ready to cover your common hollyhock in the event of a late frost.

USDA Zone Info for Sonora

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 Sonora

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