When to Plant Hollyhocks in Union City, CA

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.

A way of making a decision about when it's possible to plant hollyhocks is to consult the USDA zone info for Union City.


Planting Calendar for Hollyhocks

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

Hollyhocks do well in moderate cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant hollyhocks
Possibly ok, but a risky time to plant hollyhocks
Probably not a good time to plant hollyhocks

The earliest that you can plant hollyhocks in Union City 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. You probably don't want to wait any later than that or else your hollyhocks may not have a chance to fully mature. You can get started a few weeks earlier by starting your hollyhocks indoors.

Last Frost Date

In Union City 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.

Since the USDA zone info for Union City may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Union City there is a last frost after January 31 be ready to protect your hollyhocks in the event of one of those late frosts.

USDA Zone Info for Union City

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 Low30°F
Highest Expected Low35°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 Union City

You may be interested in your other planting guides for Union City.