One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Fairfield you can determine when to plant onions by looking at 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.

You can plant onions a lot 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 Fairfield 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 really do well. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

The average date of last frost is April 15 in Fairfield. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that USDA zone info for Fairfield may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Fairfield last frost occurs after April 15 so be sure to be ready to cover your onions if you have a surprise late frost.

USDA Zone Info for Fairfield

Here is the info for USDA Zone 5b.

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

Plants to Grow in Fairfield

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