When to Plant Onions in Seaside, OR

One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Seaside you can figure out when you can plant onions by reviewing the USDA zone info.


Planting Calendar for Onions

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

Onions tend to make it in a bit of cold which tells us 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 Seaside 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 grow to maturity. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

The average date of last frost is February 15 in Seaside. In the coldest months of winter you should expect an average low temperature of 20°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Seaside and it is different every year. Since half of the time in Seaside there is a last frost after February 15 be ready to protect your onions if you have a surprise late frost.

USDA Zone Info for Seaside

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 Seaside

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