One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

You can estimate when it's a good idea to plant common hollyhock in Millbrae 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 are moderately cold tolerant which means that you can get them planted earlier than plants that are more sensitive to the cold.

The earliest that you can plant common hollyhock in Millbrae 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 little bit earlier by starting your common hollyhock indoors.

Last Frost Date

In Millbrae the average date of last frost happens on January 31. In the coldest months of winter you can expect an average low temperature of 30°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Millbrae and it is different every year. Half of the time in Millbrae last frost occurs after January 31 so always be ready to protect your common hollyhock in the event of a late frost.

USDA Zone Info for Millbrae

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Millbrae

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