When can I plant Onions in Zone 12b

One of the best tools that we have as gardeners to help us figure out our 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 our area.

You can determine when to plant onions in Zone 12b by looking at the USDA zone info.


Planting Calendar for Onions

Frost tolerance for onions: Very tolerant of frost.
When you should plant them: Up to 7 weeks before last frost.

Since onions are very cold tolerant you can plant them quite a bit earlier in the year than more sensitive plants.

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

The earliest that you can plant onions in Zone 12b 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 onions and expect a good harvest is probably November. If you wait any later than that and your onions may not have a chance to fully mature. If you are starting your onions indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Zone 12b it never frosts. We can expect an average low temperature of 55°F in the coldest months of winter.

Since the USDA zone info for Zone 12b is not always accurate our actual date of last frost will vary from year to year. Since it never frosts in Zone 12b you do not have to be ready to cover your onions if we have a surprise late frost.

USDA Zone Info for Zone 12b

Here is the info for USDA Zone 12b.

Average Date of Last Frost (spring)Never
Average Date of First Frost (fall)Never
Lowest Expected Low55°F
Highest Expected Low60°F

This means that on a really cold year, the coldest it will get is 55°F. On most years you should be prepared to experience lows near 60°F.

Plants to Grow in Zone 12b

You may be interested in our other planting guides for Zone 12b.