Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Chula Vista should be reviewed to estimate when it's possible to plant tree onions.

Planting Calendar for Tree onions

Frost tolerance for tree onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Tree onions are barely cold tolerant which means that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant tree onions in Chula Vista is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant tree onions and expect a good harvest is probably September. Any later than that and your tree onions may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your tree onions indoors.

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 there is a last frost after January 31 be ready to cover your tree onions in the event of one of those late frosts.

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.