One of the first steps you take when you are determining your gardening schedule is find your 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.

By checking out the USDA zone info for Aurora it's possible to estimate when it's the best time to plant onions.

Planting Calendar for Onions

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

Onions do well in cold which tells us that you can get them planted much earlier than other frost tender plants.

The earliest that you can plant onions in Aurora 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 fully mature. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Aurora. In the coldest months of winter you can expect an average low temperature of -5°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Aurora and it changes from year to year. Half of the time in Aurora you get surprised by a frost after April 15 so make sure that you are prepared to protect your onions if you have a surprise late frost.

USDA Zone Info for Aurora

Here is the info for USDA Zone 6b.

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

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

Plants to Grow in Aurora

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