When to Plant Onions in Duarte, CA

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Duarte it's a good idea to determine when it's the best time to plant onions.


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 quite a bit of cold which tells us that you can plant them earlier in the year than other frost tender 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 Duarte 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. Any later than that and your onions may not have a chance to grow to maturity. Starting your onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Duarte the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 30°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Duarte and it can change quite a bit from year to year. Half of the time in Duarte it frosts late in the year after January 31 so be sure to be ready to cover your onions if you have a late frost.

USDA Zone Info for Duarte

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 Duarte

You may be interested in your other planting guides for Duarte.