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 common way of figuring out when it's the best time to plant onions is to examine the USDA zone info for Zone 11a.

Planting Calendar for Onions

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

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

The earliest that you can plant onions in Zone 11a 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. You probably don't want to wait any later than that or else 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 little bit earlier.

Last Frost Date

In Zone 11a it never frosts. In the coldest months of winter you can expect an average low temperature of 40°F.

Since the USDA zone info for Zone 11a is an average the actual date of last frost will vary from year to year. Since it never frosts in Zone 11a you do not have to be ready to cover your onions if you have one of those late frosts.

USDA Zone Info for Zone 11a

Here is the info for USDA Zone 11a.

Average Date of Last Frost (spring)	Never
Average Date of First Frost (fall)	Never
Lowest Expected Low	40°F
Highest Expected Low	45°F

This means that on a really cold year, the coldest it will get is 40°F. On most years you should be prepared to experience lows near 45°F.

Plants to Grow in Zone 11a

You may be interested in your other planting guides for Zone 11a.