When to Plant Onions in Auburn, WA

One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when it's the best time to plant onions is to look at the USDA zone info for Auburn.


Planting Calendar for Onions

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

Onions do well in quite a bit of cold which means that you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

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 Auburn 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 onions and expect a good harvest is probably September. If you wait any later than that and your onions may not have a chance to really do well. Starting your onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Auburn. In the coldest months of winter you can expect an average low temperature of 15°F.

It's important to remember that USDA zone info for Auburn is not always accurate and the actual date of last frost is different every year. Half of the time in Auburn you get surprised by a frost after March 15 so make sure that you are prepared to cover your onions in the event of one of those late frosts.

USDA Zone Info for Auburn

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)March 15
Average Date of First Frost (fall)November 15
Lowest Expected Low15°F
Highest Expected Low20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Auburn

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