One of the first steps you take when you are getting a good idea 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.

A common way of figuring out when to plant onions is to use the USDA zone info for Centralia.

Planting Calendar for Onions

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

Onions do ok in cold weather which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant onions in Centralia 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. Any later than that and your onions may not have a chance to grow to maturity. If you are starting your onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Centralia. It might get as low as -10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Centralia may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Centralia you get surprised by a frost after April 15 be ready to protect your onions in the event of a late frost.

USDA Zone Info for Centralia

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Centralia

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