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

The first chance to plant welsh onion in Cerritos can be figured out by looking at the USDA zone info.

Planting Calendar for Welsh onion

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

Welsh onion do ok in some cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant welsh onion in Cerritos 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 welsh onion and expect a good harvest is probably September. Any later than that and your welsh onion may not have a chance to really do well. You can get started a couple of weeks earlier by starting your welsh onion indoors.

Last Frost Date

In Cerritos the average date of last frost happens on January 31. It might get as low as 35°F during the coldest months of winter.

Since the USDA zone info for Cerritos is not always accurate the actual date of last frost will vary from year to year. Half of the time in Cerritos last frost occurs after January 31 so make sure that you are prepared to cover your welsh onion in the event of one of those late frosts.

USDA Zone Info for Cerritos

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 Cerritos

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