One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to figure out when it's possible to plant onions by looking at the USDA zone info for Coronado.

Planting Calendar for Onions

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

You can plant onions quite a bit earlier in the year because they are very cold tolerant.

The earliest that you can plant onions in Coronado 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. 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 Coronado the average date of last frost happens on January 31. In the coldest months of winter you can expect an average low temperature of 35°F.

Since the USDA zone info for Coronado is an average the actual date of last frost is different every year. Half of the time in Coronado you get surprised by a frost after January 31 so be sure to be ready to protect your onions if you have a surprise late frost.

USDA Zone Info for Coronado

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 Coronado

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