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.

The earliest that you can plant onions in San Carlos can be determined 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.

Since onions are very cold tolerant you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant onions in San Carlos 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. If you wait 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 couple of weeks earlier.

Last Frost Date

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

Remember that USDA zone info for San Carlos is just an average and the actual date of last frost is different every year. Since half of the time in San Carlos you get surprised by a frost after January 31 be ready to protect your onions if you have one of those late frosts.

USDA Zone Info for San Carlos

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 San Carlos

You may be interested in your other planting guides for San Carlos.