When to Plant Bunching Onions in Clarendon Hills, IL

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant bunching onions in Clarendon Hills should be estimated by checking out the USDA zone info.


Planting Calendar for Bunching Onions

Frost tolerance for bunching onions: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Since bunching onions are barely cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

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

The earliest that you can plant bunching onions in Clarendon Hills is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant bunching onions and expect a good harvest is probably August. Any later than that and your bunching onions may not have a chance to really do well. If you are starting your bunching onions indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Clarendon Hills. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Clarendon Hills may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Clarendon Hills you get a frost after April 15 so always be ready to cover your bunching onions if you have a late frost.

USDA Zone Info for Clarendon Hills

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 Clarendon Hills

You may be interested in your other planting guides for Clarendon Hills.