When can I plant Onions in Zone 9a

One of the first steps we take when we are getting a good idea our gardening schedule is find our USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for our area.

The first chance to plant onions in Zone 9a can be estimated by looking at the USDA zone info.


Planting Calendar for Onions

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

Since onions do well in cold you can plant them much earlier in the year than other frost tender plants.

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

The earliest that you can plant onions in Zone 9a 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. You probably don't want to wait any later than that or else your onions may not have a chance to really do well. Starting your onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Zone 9a. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Zone 9a is not always accurate our actual date of last frost is different every year. Half of the time in Zone 9a it frosts late in the year after February 15 so just be sure to be ready to protect your onions if we have a late frost.

USDA Zone Info for Zone 9a

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)February 15
Average Date of First Frost (fall)December 15
Lowest Expected Low20°F
Highest Expected Low25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Zone 9a

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