When to Plant Onions in Olney, IL

Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Olney you can figure out when to plant onions by referring to 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.

Onions can survive in pretty solid cold which tells us that you can plant them a lot earlier in the year than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant onions
Possibly ok, but a risky time to plant onions
Probably not a good time to plant onions

The earliest that you can plant onions in Olney 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 really do well. 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 April 15 in Olney. In the coldest months of winter you should expect an average low temperature of -10°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Olney and it changes from year to year. Half of the time in Olney you get a frost after April 15 so make sure that you are prepared to protect your onions if you have one of those late frosts.

USDA Zone Info for Olney

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 Olney

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