The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when to plant hollyhocks by reviewing the USDA zone info for Los Altos.

Planting Calendar for Hollyhocks

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

Hollyhocks can survive in mild cold which tells us that you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant hollyhocks in Los Altos 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 hollyhocks and expect a good harvest is probably October. If you wait any later than that and your hollyhocks may not have a chance to fully mature. You can get started a little bit earlier by starting your hollyhocks indoors.

Last Frost Date

In Los Altos 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.

Just be sure to remember that USDA zone info for Los Altos is an average and the actual date of last frost changes from year to year. Half of the time in Los Altos you get surprised by a frost after February 15 so make sure that you are prepared to cover your hollyhocks in the event of a surprise late frost.

USDA Zone Info for Los Altos

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 Los Altos

You may be interested in your other planting guides for Los Altos.