Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to estimate when it's possible to plant onions by checking out the USDA zone info for Fairfax.

Planting Calendar for Onions

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

Since onions do well in cold you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant onions in Fairfax 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. 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 Fairfax. You can expect an average low temperature of 0°F in the coldest months of winter.

Always keep in mind that USDA zone info for Fairfax may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Fairfax it frosts late in the year after April 15 be ready to protect your onions in the event of a late frost.

USDA Zone Info for Fairfax

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Fairfax

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