One of the best tools that you have as gardeners to help us determine 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.

By using the USDA zone info for Chino Hills you should be able to figure out when 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 ok in cold weather which means that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant onions in Chino Hills 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 really do well. You can get started a little bit earlier by starting your onions indoors.

Last Frost Date

The average date of last frost is January 31 in Chino Hills. You should expect an average low temperature of 30°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Chino Hills and it is different every year. Since half of the time in Chino Hills there is a last frost after January 31 be ready to protect your onions in the event of a surprise late frost.

USDA Zone Info for Chino Hills

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 Low	30°F
Highest Expected Low	35°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 Chino Hills

You may be interested in your other planting guides for Chino Hills.