The USDA Zone info is a great tool for gardeners to help us figure out your gardening 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 hollyhocks in Palo Alto should be estimated by looking at the USDA zone info.

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 moderate cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant hollyhocks in Palo Alto 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. If you are starting your hollyhocks indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Palo Alto. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Palo Alto is just an average the actual date of last frost is different every year. Since half of the time in Palo Alto it frosts late in the year after February 15 be ready to cover your hollyhocks if you have one of those late frosts.

USDA Zone Info for Palo Alto

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 Palo Alto

You may be interested in your other planting guides for Palo Alto.