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.

In Chula Vista you can figure out when it's possible to plant onions by checking out the USDA zone info.

Planting Calendar for Onions

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

Onions can survive in quite a bit of cold which means that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant onions in Chula Vista 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 October. You probably don't want to wait any later than that or else your onions may not have a chance to grow to maturity. If you are starting your onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Chula Vista. In the coldest months of winter you should expect an average low temperature of 35°F.

Always keep in mind that USDA zone info for Chula Vista may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Chula Vista you get a frost after January 31 be ready to protect your onions in the event of a late frost.

USDA Zone Info for Chula Vista

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Chula Vista

You may be interested in your other planting guides for Chula Vista.