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.

You should be able to determine when it's the best time to plant onions by referring to the USDA zone info for Snohomish.

Planting Calendar for Onions

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

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

The earliest that you can plant onions in Snohomish 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. You probably don't want to wait any later than that or else your onions may not have a chance to grow to maturity. 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 Snohomish. In the coldest months of winter you should expect an average low temperature of 15°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Snohomish and it will vary from year to year. Since half of the time in Snohomish you get a frost after March 15 be ready to cover your onions in the event of a surprise late frost.

USDA Zone Info for Snohomish

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 Low	15°F
Highest Expected Low	20°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 Snohomish

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