The USDA Zone info is a great tool for gardeners to help us determine 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.

The best time to plant welsh onion in Zone 10b can be determined 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 are one of those plants that can tolerate a tiny bit of cold weather which means that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant welsh onion in Zone 10b 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 grow to maturity. If you are starting your welsh onion indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Zone 10b. In the coldest months of winter you should expect an average low temperature of 35°F.

Just be sure to remember that USDA zone info for Zone 10b may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Zone 10b you get a frost after January 31 be ready to cover your welsh onion if you have a late frost.

USDA Zone Info for Zone 10b

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 Zone 10b

You may be interested in your other planting guides for Zone 10b.