When can I plant Welsh onion in Zone 9b

One of the first steps we take when we are determining our gardening schedule is find our USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

In Zone 9b you can figure out when it's a good idea to plant welsh onion 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 you should plant them: Up to 3 weeks before last frost.

You can plant welsh onion a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant welsh onion
Possibly ok, but a risky time to plant welsh onion
Probably not a good time to plant welsh onion

The earliest that you can plant welsh onion in Zone 9b 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. If you wait any later than that and your welsh onion may not have a chance to really do well. Starting your welsh onion indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Zone 9b. We should expect an average low temperature of 25°F in the coldest months of winter.

It's important to remember that USDA zone info for Zone 9b is an average and our actual date of last frost can change quite a bit from year to year. Since half of the time in Zone 9b we get surprised by a frost after February 15 be ready to cover your welsh onion if we have a surprise late frost.

USDA Zone Info for Zone 9b

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)February 15
Average Date of First Frost (fall)December 15
Lowest Expected Low25°F
Highest Expected Low30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Zone 9b

You may be interested in our other planting guides for Zone 9b.